usb: Using correct way to clear usb3.0 device's remote wakeup feature.
[~shefty/rdma-dev.git] / drivers / usb / core / hub.c
1 /*
2  * USB hub driver.
3  *
4  * (C) Copyright 1999 Linus Torvalds
5  * (C) Copyright 1999 Johannes Erdfelt
6  * (C) Copyright 1999 Gregory P. Smith
7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8  *
9  */
10
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/completion.h>
16 #include <linux/sched.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/ioctl.h>
20 #include <linux/usb.h>
21 #include <linux/usbdevice_fs.h>
22 #include <linux/usb/hcd.h>
23 #include <linux/usb/otg.h>
24 #include <linux/usb/quirks.h>
25 #include <linux/kthread.h>
26 #include <linux/mutex.h>
27 #include <linux/freezer.h>
28 #include <linux/random.h>
29
30 #include <asm/uaccess.h>
31 #include <asm/byteorder.h>
32
33 #include "usb.h"
34
35 /* if we are in debug mode, always announce new devices */
36 #ifdef DEBUG
37 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
38 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES
39 #endif
40 #endif
41
42 #define USB_VENDOR_GENESYS_LOGIC                0x05e3
43 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND        0x01
44
45 struct usb_port {
46         struct usb_device *child;
47         struct device dev;
48         struct dev_state *port_owner;
49         enum usb_port_connect_type connect_type;
50 };
51
52 struct usb_hub {
53         struct device           *intfdev;       /* the "interface" device */
54         struct usb_device       *hdev;
55         struct kref             kref;
56         struct urb              *urb;           /* for interrupt polling pipe */
57
58         /* buffer for urb ... with extra space in case of babble */
59         char                    (*buffer)[8];
60         union {
61                 struct usb_hub_status   hub;
62                 struct usb_port_status  port;
63         }                       *status;        /* buffer for status reports */
64         struct mutex            status_mutex;   /* for the status buffer */
65
66         int                     error;          /* last reported error */
67         int                     nerrors;        /* track consecutive errors */
68
69         struct list_head        event_list;     /* hubs w/data or errs ready */
70         unsigned long           event_bits[1];  /* status change bitmask */
71         unsigned long           change_bits[1]; /* ports with logical connect
72                                                         status change */
73         unsigned long           busy_bits[1];   /* ports being reset or
74                                                         resumed */
75         unsigned long           removed_bits[1]; /* ports with a "removed"
76                                                         device present */
77         unsigned long           wakeup_bits[1]; /* ports that have signaled
78                                                         remote wakeup */
79 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
80 #error event_bits[] is too short!
81 #endif
82
83         struct usb_hub_descriptor *descriptor;  /* class descriptor */
84         struct usb_tt           tt;             /* Transaction Translator */
85
86         unsigned                mA_per_port;    /* current for each child */
87
88         unsigned                limited_power:1;
89         unsigned                quiescing:1;
90         unsigned                disconnected:1;
91
92         unsigned                quirk_check_port_auto_suspend:1;
93
94         unsigned                has_indicators:1;
95         u8                      indicator[USB_MAXCHILDREN];
96         struct delayed_work     leds;
97         struct delayed_work     init_work;
98         struct usb_port         **ports;
99 };
100
101 static inline int hub_is_superspeed(struct usb_device *hdev)
102 {
103         return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS);
104 }
105
106 /* Protect struct usb_device->state and ->children members
107  * Note: Both are also protected by ->dev.sem, except that ->state can
108  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
109 static DEFINE_SPINLOCK(device_state_lock);
110
111 /* khubd's worklist and its lock */
112 static DEFINE_SPINLOCK(hub_event_lock);
113 static LIST_HEAD(hub_event_list);       /* List of hubs needing servicing */
114
115 /* Wakes up khubd */
116 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
117
118 static struct task_struct *khubd_task;
119
120 /* cycle leds on hubs that aren't blinking for attention */
121 static bool blinkenlights = 0;
122 module_param (blinkenlights, bool, S_IRUGO);
123 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
124
125 /*
126  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
127  * 10 seconds to send reply for the initial 64-byte descriptor request.
128  */
129 /* define initial 64-byte descriptor request timeout in milliseconds */
130 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
131 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
132 MODULE_PARM_DESC(initial_descriptor_timeout,
133                 "initial 64-byte descriptor request timeout in milliseconds "
134                 "(default 5000 - 5.0 seconds)");
135
136 /*
137  * As of 2.6.10 we introduce a new USB device initialization scheme which
138  * closely resembles the way Windows works.  Hopefully it will be compatible
139  * with a wider range of devices than the old scheme.  However some previously
140  * working devices may start giving rise to "device not accepting address"
141  * errors; if that happens the user can try the old scheme by adjusting the
142  * following module parameters.
143  *
144  * For maximum flexibility there are two boolean parameters to control the
145  * hub driver's behavior.  On the first initialization attempt, if the
146  * "old_scheme_first" parameter is set then the old scheme will be used,
147  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
148  * is set, then the driver will make another attempt, using the other scheme.
149  */
150 static bool old_scheme_first = 0;
151 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
152 MODULE_PARM_DESC(old_scheme_first,
153                  "start with the old device initialization scheme");
154
155 static bool use_both_schemes = 1;
156 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
157 MODULE_PARM_DESC(use_both_schemes,
158                 "try the other device initialization scheme if the "
159                 "first one fails");
160
161 /* Mutual exclusion for EHCI CF initialization.  This interferes with
162  * port reset on some companion controllers.
163  */
164 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
165 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
166
167 #define HUB_DEBOUNCE_TIMEOUT    1500
168 #define HUB_DEBOUNCE_STEP         25
169 #define HUB_DEBOUNCE_STABLE      100
170
171 #define to_usb_port(_dev) \
172         container_of(_dev, struct usb_port, dev)
173
174 static int usb_reset_and_verify_device(struct usb_device *udev);
175
176 static inline char *portspeed(struct usb_hub *hub, int portstatus)
177 {
178         if (hub_is_superspeed(hub->hdev))
179                 return "5.0 Gb/s";
180         if (portstatus & USB_PORT_STAT_HIGH_SPEED)
181                 return "480 Mb/s";
182         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
183                 return "1.5 Mb/s";
184         else
185                 return "12 Mb/s";
186 }
187
188 /* Note that hdev or one of its children must be locked! */
189 static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
190 {
191         if (!hdev || !hdev->actconfig || !hdev->maxchild)
192                 return NULL;
193         return usb_get_intfdata(hdev->actconfig->interface[0]);
194 }
195
196 static int usb_device_supports_lpm(struct usb_device *udev)
197 {
198         /* USB 2.1 (and greater) devices indicate LPM support through
199          * their USB 2.0 Extended Capabilities BOS descriptor.
200          */
201         if (udev->speed == USB_SPEED_HIGH) {
202                 if (udev->bos->ext_cap &&
203                         (USB_LPM_SUPPORT &
204                          le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
205                         return 1;
206                 return 0;
207         }
208
209         /* All USB 3.0 must support LPM, but we need their max exit latency
210          * information from the SuperSpeed Extended Capabilities BOS descriptor.
211          */
212         if (!udev->bos->ss_cap) {
213                 dev_warn(&udev->dev, "No LPM exit latency info found.  "
214                                 "Power management will be impacted.\n");
215                 return 0;
216         }
217         if (udev->parent->lpm_capable)
218                 return 1;
219
220         dev_warn(&udev->dev, "Parent hub missing LPM exit latency info.  "
221                         "Power management will be impacted.\n");
222         return 0;
223 }
224
225 /*
226  * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
227  * either U1 or U2.
228  */
229 static void usb_set_lpm_mel(struct usb_device *udev,
230                 struct usb3_lpm_parameters *udev_lpm_params,
231                 unsigned int udev_exit_latency,
232                 struct usb_hub *hub,
233                 struct usb3_lpm_parameters *hub_lpm_params,
234                 unsigned int hub_exit_latency)
235 {
236         unsigned int total_mel;
237         unsigned int device_mel;
238         unsigned int hub_mel;
239
240         /*
241          * Calculate the time it takes to transition all links from the roothub
242          * to the parent hub into U0.  The parent hub must then decode the
243          * packet (hub header decode latency) to figure out which port it was
244          * bound for.
245          *
246          * The Hub Header decode latency is expressed in 0.1us intervals (0x1
247          * means 0.1us).  Multiply that by 100 to get nanoseconds.
248          */
249         total_mel = hub_lpm_params->mel +
250                 (hub->descriptor->u.ss.bHubHdrDecLat * 100);
251
252         /*
253          * How long will it take to transition the downstream hub's port into
254          * U0?  The greater of either the hub exit latency or the device exit
255          * latency.
256          *
257          * The BOS U1/U2 exit latencies are expressed in 1us intervals.
258          * Multiply that by 1000 to get nanoseconds.
259          */
260         device_mel = udev_exit_latency * 1000;
261         hub_mel = hub_exit_latency * 1000;
262         if (device_mel > hub_mel)
263                 total_mel += device_mel;
264         else
265                 total_mel += hub_mel;
266
267         udev_lpm_params->mel = total_mel;
268 }
269
270 /*
271  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
272  * a transition from either U1 or U2.
273  */
274 static void usb_set_lpm_pel(struct usb_device *udev,
275                 struct usb3_lpm_parameters *udev_lpm_params,
276                 unsigned int udev_exit_latency,
277                 struct usb_hub *hub,
278                 struct usb3_lpm_parameters *hub_lpm_params,
279                 unsigned int hub_exit_latency,
280                 unsigned int port_to_port_exit_latency)
281 {
282         unsigned int first_link_pel;
283         unsigned int hub_pel;
284
285         /*
286          * First, the device sends an LFPS to transition the link between the
287          * device and the parent hub into U0.  The exit latency is the bigger of
288          * the device exit latency or the hub exit latency.
289          */
290         if (udev_exit_latency > hub_exit_latency)
291                 first_link_pel = udev_exit_latency * 1000;
292         else
293                 first_link_pel = hub_exit_latency * 1000;
294
295         /*
296          * When the hub starts to receive the LFPS, there is a slight delay for
297          * it to figure out that one of the ports is sending an LFPS.  Then it
298          * will forward the LFPS to its upstream link.  The exit latency is the
299          * delay, plus the PEL that we calculated for this hub.
300          */
301         hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
302
303         /*
304          * According to figure C-7 in the USB 3.0 spec, the PEL for this device
305          * is the greater of the two exit latencies.
306          */
307         if (first_link_pel > hub_pel)
308                 udev_lpm_params->pel = first_link_pel;
309         else
310                 udev_lpm_params->pel = hub_pel;
311 }
312
313 /*
314  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
315  * when a device initiates a transition to U0, until when it will receive the
316  * first packet from the host controller.
317  *
318  * Section C.1.5.1 describes the four components to this:
319  *  - t1: device PEL
320  *  - t2: time for the ERDY to make it from the device to the host.
321  *  - t3: a host-specific delay to process the ERDY.
322  *  - t4: time for the packet to make it from the host to the device.
323  *
324  * t3 is specific to both the xHCI host and the platform the host is integrated
325  * into.  The Intel HW folks have said it's negligible, FIXME if a different
326  * vendor says otherwise.
327  */
328 static void usb_set_lpm_sel(struct usb_device *udev,
329                 struct usb3_lpm_parameters *udev_lpm_params)
330 {
331         struct usb_device *parent;
332         unsigned int num_hubs;
333         unsigned int total_sel;
334
335         /* t1 = device PEL */
336         total_sel = udev_lpm_params->pel;
337         /* How many external hubs are in between the device & the root port. */
338         for (parent = udev->parent, num_hubs = 0; parent->parent;
339                         parent = parent->parent)
340                 num_hubs++;
341         /* t2 = 2.1us + 250ns * (num_hubs - 1) */
342         if (num_hubs > 0)
343                 total_sel += 2100 + 250 * (num_hubs - 1);
344
345         /* t4 = 250ns * num_hubs */
346         total_sel += 250 * num_hubs;
347
348         udev_lpm_params->sel = total_sel;
349 }
350
351 static void usb_set_lpm_parameters(struct usb_device *udev)
352 {
353         struct usb_hub *hub;
354         unsigned int port_to_port_delay;
355         unsigned int udev_u1_del;
356         unsigned int udev_u2_del;
357         unsigned int hub_u1_del;
358         unsigned int hub_u2_del;
359
360         if (!udev->lpm_capable || udev->speed != USB_SPEED_SUPER)
361                 return;
362
363         hub = hdev_to_hub(udev->parent);
364         /* It doesn't take time to transition the roothub into U0, since it
365          * doesn't have an upstream link.
366          */
367         if (!hub)
368                 return;
369
370         udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
371         udev_u2_del = udev->bos->ss_cap->bU2DevExitLat;
372         hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
373         hub_u2_del = udev->parent->bos->ss_cap->bU2DevExitLat;
374
375         usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
376                         hub, &udev->parent->u1_params, hub_u1_del);
377
378         usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
379                         hub, &udev->parent->u2_params, hub_u2_del);
380
381         /*
382          * Appendix C, section C.2.2.2, says that there is a slight delay from
383          * when the parent hub notices the downstream port is trying to
384          * transition to U0 to when the hub initiates a U0 transition on its
385          * upstream port.  The section says the delays are tPort2PortU1EL and
386          * tPort2PortU2EL, but it doesn't define what they are.
387          *
388          * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
389          * about the same delays.  Use the maximum delay calculations from those
390          * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
391          * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
392          * assume the device exit latencies they are talking about are the hub
393          * exit latencies.
394          *
395          * What do we do if the U2 exit latency is less than the U1 exit
396          * latency?  It's possible, although not likely...
397          */
398         port_to_port_delay = 1;
399
400         usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
401                         hub, &udev->parent->u1_params, hub_u1_del,
402                         port_to_port_delay);
403
404         if (hub_u2_del > hub_u1_del)
405                 port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
406         else
407                 port_to_port_delay = 1 + hub_u1_del;
408
409         usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
410                         hub, &udev->parent->u2_params, hub_u2_del,
411                         port_to_port_delay);
412
413         /* Now that we've got PEL, calculate SEL. */
414         usb_set_lpm_sel(udev, &udev->u1_params);
415         usb_set_lpm_sel(udev, &udev->u2_params);
416 }
417
418 /* USB 2.0 spec Section 11.24.4.5 */
419 static int get_hub_descriptor(struct usb_device *hdev, void *data)
420 {
421         int i, ret, size;
422         unsigned dtype;
423
424         if (hub_is_superspeed(hdev)) {
425                 dtype = USB_DT_SS_HUB;
426                 size = USB_DT_SS_HUB_SIZE;
427         } else {
428                 dtype = USB_DT_HUB;
429                 size = sizeof(struct usb_hub_descriptor);
430         }
431
432         for (i = 0; i < 3; i++) {
433                 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
434                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
435                         dtype << 8, 0, data, size,
436                         USB_CTRL_GET_TIMEOUT);
437                 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
438                         return ret;
439         }
440         return -EINVAL;
441 }
442
443 /*
444  * USB 2.0 spec Section 11.24.2.1
445  */
446 static int clear_hub_feature(struct usb_device *hdev, int feature)
447 {
448         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
449                 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
450 }
451
452 /*
453  * USB 2.0 spec Section 11.24.2.2
454  */
455 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
456 {
457         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
458                 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
459                 NULL, 0, 1000);
460 }
461
462 /*
463  * USB 2.0 spec Section 11.24.2.13
464  */
465 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
466 {
467         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
468                 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
469                 NULL, 0, 1000);
470 }
471
472 /*
473  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
474  * for info about using port indicators
475  */
476 static void set_port_led(
477         struct usb_hub *hub,
478         int port1,
479         int selector
480 )
481 {
482         int status = set_port_feature(hub->hdev, (selector << 8) | port1,
483                         USB_PORT_FEAT_INDICATOR);
484         if (status < 0)
485                 dev_dbg (hub->intfdev,
486                         "port %d indicator %s status %d\n",
487                         port1,
488                         ({ char *s; switch (selector) {
489                         case HUB_LED_AMBER: s = "amber"; break;
490                         case HUB_LED_GREEN: s = "green"; break;
491                         case HUB_LED_OFF: s = "off"; break;
492                         case HUB_LED_AUTO: s = "auto"; break;
493                         default: s = "??"; break;
494                         }; s; }),
495                         status);
496 }
497
498 #define LED_CYCLE_PERIOD        ((2*HZ)/3)
499
500 static void led_work (struct work_struct *work)
501 {
502         struct usb_hub          *hub =
503                 container_of(work, struct usb_hub, leds.work);
504         struct usb_device       *hdev = hub->hdev;
505         unsigned                i;
506         unsigned                changed = 0;
507         int                     cursor = -1;
508
509         if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
510                 return;
511
512         for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
513                 unsigned        selector, mode;
514
515                 /* 30%-50% duty cycle */
516
517                 switch (hub->indicator[i]) {
518                 /* cycle marker */
519                 case INDICATOR_CYCLE:
520                         cursor = i;
521                         selector = HUB_LED_AUTO;
522                         mode = INDICATOR_AUTO;
523                         break;
524                 /* blinking green = sw attention */
525                 case INDICATOR_GREEN_BLINK:
526                         selector = HUB_LED_GREEN;
527                         mode = INDICATOR_GREEN_BLINK_OFF;
528                         break;
529                 case INDICATOR_GREEN_BLINK_OFF:
530                         selector = HUB_LED_OFF;
531                         mode = INDICATOR_GREEN_BLINK;
532                         break;
533                 /* blinking amber = hw attention */
534                 case INDICATOR_AMBER_BLINK:
535                         selector = HUB_LED_AMBER;
536                         mode = INDICATOR_AMBER_BLINK_OFF;
537                         break;
538                 case INDICATOR_AMBER_BLINK_OFF:
539                         selector = HUB_LED_OFF;
540                         mode = INDICATOR_AMBER_BLINK;
541                         break;
542                 /* blink green/amber = reserved */
543                 case INDICATOR_ALT_BLINK:
544                         selector = HUB_LED_GREEN;
545                         mode = INDICATOR_ALT_BLINK_OFF;
546                         break;
547                 case INDICATOR_ALT_BLINK_OFF:
548                         selector = HUB_LED_AMBER;
549                         mode = INDICATOR_ALT_BLINK;
550                         break;
551                 default:
552                         continue;
553                 }
554                 if (selector != HUB_LED_AUTO)
555                         changed = 1;
556                 set_port_led(hub, i + 1, selector);
557                 hub->indicator[i] = mode;
558         }
559         if (!changed && blinkenlights) {
560                 cursor++;
561                 cursor %= hub->descriptor->bNbrPorts;
562                 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
563                 hub->indicator[cursor] = INDICATOR_CYCLE;
564                 changed++;
565         }
566         if (changed)
567                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
568 }
569
570 /* use a short timeout for hub/port status fetches */
571 #define USB_STS_TIMEOUT         1000
572 #define USB_STS_RETRIES         5
573
574 /*
575  * USB 2.0 spec Section 11.24.2.6
576  */
577 static int get_hub_status(struct usb_device *hdev,
578                 struct usb_hub_status *data)
579 {
580         int i, status = -ETIMEDOUT;
581
582         for (i = 0; i < USB_STS_RETRIES &&
583                         (status == -ETIMEDOUT || status == -EPIPE); i++) {
584                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
585                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
586                         data, sizeof(*data), USB_STS_TIMEOUT);
587         }
588         return status;
589 }
590
591 /*
592  * USB 2.0 spec Section 11.24.2.7
593  */
594 static int get_port_status(struct usb_device *hdev, int port1,
595                 struct usb_port_status *data)
596 {
597         int i, status = -ETIMEDOUT;
598
599         for (i = 0; i < USB_STS_RETRIES &&
600                         (status == -ETIMEDOUT || status == -EPIPE); i++) {
601                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
602                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
603                         data, sizeof(*data), USB_STS_TIMEOUT);
604         }
605         return status;
606 }
607
608 static int hub_port_status(struct usb_hub *hub, int port1,
609                 u16 *status, u16 *change)
610 {
611         int ret;
612
613         mutex_lock(&hub->status_mutex);
614         ret = get_port_status(hub->hdev, port1, &hub->status->port);
615         if (ret < 4) {
616                 dev_err(hub->intfdev,
617                         "%s failed (err = %d)\n", __func__, ret);
618                 if (ret >= 0)
619                         ret = -EIO;
620         } else {
621                 *status = le16_to_cpu(hub->status->port.wPortStatus);
622                 *change = le16_to_cpu(hub->status->port.wPortChange);
623
624                 ret = 0;
625         }
626         mutex_unlock(&hub->status_mutex);
627         return ret;
628 }
629
630 static void kick_khubd(struct usb_hub *hub)
631 {
632         unsigned long   flags;
633
634         spin_lock_irqsave(&hub_event_lock, flags);
635         if (!hub->disconnected && list_empty(&hub->event_list)) {
636                 list_add_tail(&hub->event_list, &hub_event_list);
637
638                 /* Suppress autosuspend until khubd runs */
639                 usb_autopm_get_interface_no_resume(
640                                 to_usb_interface(hub->intfdev));
641                 wake_up(&khubd_wait);
642         }
643         spin_unlock_irqrestore(&hub_event_lock, flags);
644 }
645
646 void usb_kick_khubd(struct usb_device *hdev)
647 {
648         struct usb_hub *hub = hdev_to_hub(hdev);
649
650         if (hub)
651                 kick_khubd(hub);
652 }
653
654 /*
655  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
656  * Notification, which indicates it had initiated remote wakeup.
657  *
658  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
659  * device initiates resume, so the USB core will not receive notice of the
660  * resume through the normal hub interrupt URB.
661  */
662 void usb_wakeup_notification(struct usb_device *hdev,
663                 unsigned int portnum)
664 {
665         struct usb_hub *hub;
666
667         if (!hdev)
668                 return;
669
670         hub = hdev_to_hub(hdev);
671         if (hub) {
672                 set_bit(portnum, hub->wakeup_bits);
673                 kick_khubd(hub);
674         }
675 }
676 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
677
678 /* completion function, fires on port status changes and various faults */
679 static void hub_irq(struct urb *urb)
680 {
681         struct usb_hub *hub = urb->context;
682         int status = urb->status;
683         unsigned i;
684         unsigned long bits;
685
686         switch (status) {
687         case -ENOENT:           /* synchronous unlink */
688         case -ECONNRESET:       /* async unlink */
689         case -ESHUTDOWN:        /* hardware going away */
690                 return;
691
692         default:                /* presumably an error */
693                 /* Cause a hub reset after 10 consecutive errors */
694                 dev_dbg (hub->intfdev, "transfer --> %d\n", status);
695                 if ((++hub->nerrors < 10) || hub->error)
696                         goto resubmit;
697                 hub->error = status;
698                 /* FALL THROUGH */
699
700         /* let khubd handle things */
701         case 0:                 /* we got data:  port status changed */
702                 bits = 0;
703                 for (i = 0; i < urb->actual_length; ++i)
704                         bits |= ((unsigned long) ((*hub->buffer)[i]))
705                                         << (i*8);
706                 hub->event_bits[0] = bits;
707                 break;
708         }
709
710         hub->nerrors = 0;
711
712         /* Something happened, let khubd figure it out */
713         kick_khubd(hub);
714
715 resubmit:
716         if (hub->quiescing)
717                 return;
718
719         if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
720                         && status != -ENODEV && status != -EPERM)
721                 dev_err (hub->intfdev, "resubmit --> %d\n", status);
722 }
723
724 /* USB 2.0 spec Section 11.24.2.3 */
725 static inline int
726 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
727 {
728         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
729                                HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
730                                tt, NULL, 0, 1000);
731 }
732
733 /*
734  * enumeration blocks khubd for a long time. we use keventd instead, since
735  * long blocking there is the exception, not the rule.  accordingly, HCDs
736  * talking to TTs must queue control transfers (not just bulk and iso), so
737  * both can talk to the same hub concurrently.
738  */
739 static void hub_tt_work(struct work_struct *work)
740 {
741         struct usb_hub          *hub =
742                 container_of(work, struct usb_hub, tt.clear_work);
743         unsigned long           flags;
744
745         spin_lock_irqsave (&hub->tt.lock, flags);
746         while (!list_empty(&hub->tt.clear_list)) {
747                 struct list_head        *next;
748                 struct usb_tt_clear     *clear;
749                 struct usb_device       *hdev = hub->hdev;
750                 const struct hc_driver  *drv;
751                 int                     status;
752
753                 next = hub->tt.clear_list.next;
754                 clear = list_entry (next, struct usb_tt_clear, clear_list);
755                 list_del (&clear->clear_list);
756
757                 /* drop lock so HCD can concurrently report other TT errors */
758                 spin_unlock_irqrestore (&hub->tt.lock, flags);
759                 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
760                 if (status)
761                         dev_err (&hdev->dev,
762                                 "clear tt %d (%04x) error %d\n",
763                                 clear->tt, clear->devinfo, status);
764
765                 /* Tell the HCD, even if the operation failed */
766                 drv = clear->hcd->driver;
767                 if (drv->clear_tt_buffer_complete)
768                         (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
769
770                 kfree(clear);
771                 spin_lock_irqsave(&hub->tt.lock, flags);
772         }
773         spin_unlock_irqrestore (&hub->tt.lock, flags);
774 }
775
776 /**
777  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
778  * @urb: an URB associated with the failed or incomplete split transaction
779  *
780  * High speed HCDs use this to tell the hub driver that some split control or
781  * bulk transaction failed in a way that requires clearing internal state of
782  * a transaction translator.  This is normally detected (and reported) from
783  * interrupt context.
784  *
785  * It may not be possible for that hub to handle additional full (or low)
786  * speed transactions until that state is fully cleared out.
787  */
788 int usb_hub_clear_tt_buffer(struct urb *urb)
789 {
790         struct usb_device       *udev = urb->dev;
791         int                     pipe = urb->pipe;
792         struct usb_tt           *tt = udev->tt;
793         unsigned long           flags;
794         struct usb_tt_clear     *clear;
795
796         /* we've got to cope with an arbitrary number of pending TT clears,
797          * since each TT has "at least two" buffers that can need it (and
798          * there can be many TTs per hub).  even if they're uncommon.
799          */
800         if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
801                 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
802                 /* FIXME recover somehow ... RESET_TT? */
803                 return -ENOMEM;
804         }
805
806         /* info that CLEAR_TT_BUFFER needs */
807         clear->tt = tt->multi ? udev->ttport : 1;
808         clear->devinfo = usb_pipeendpoint (pipe);
809         clear->devinfo |= udev->devnum << 4;
810         clear->devinfo |= usb_pipecontrol (pipe)
811                         ? (USB_ENDPOINT_XFER_CONTROL << 11)
812                         : (USB_ENDPOINT_XFER_BULK << 11);
813         if (usb_pipein (pipe))
814                 clear->devinfo |= 1 << 15;
815
816         /* info for completion callback */
817         clear->hcd = bus_to_hcd(udev->bus);
818         clear->ep = urb->ep;
819
820         /* tell keventd to clear state for this TT */
821         spin_lock_irqsave (&tt->lock, flags);
822         list_add_tail (&clear->clear_list, &tt->clear_list);
823         schedule_work(&tt->clear_work);
824         spin_unlock_irqrestore (&tt->lock, flags);
825         return 0;
826 }
827 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
828
829 /* If do_delay is false, return the number of milliseconds the caller
830  * needs to delay.
831  */
832 static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
833 {
834         int port1;
835         unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
836         unsigned delay;
837         u16 wHubCharacteristics =
838                         le16_to_cpu(hub->descriptor->wHubCharacteristics);
839
840         /* Enable power on each port.  Some hubs have reserved values
841          * of LPSM (> 2) in their descriptors, even though they are
842          * USB 2.0 hubs.  Some hubs do not implement port-power switching
843          * but only emulate it.  In all cases, the ports won't work
844          * unless we send these messages to the hub.
845          */
846         if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
847                 dev_dbg(hub->intfdev, "enabling power on all ports\n");
848         else
849                 dev_dbg(hub->intfdev, "trying to enable port power on "
850                                 "non-switchable hub\n");
851         for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
852                 set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
853
854         /* Wait at least 100 msec for power to become stable */
855         delay = max(pgood_delay, (unsigned) 100);
856         if (do_delay)
857                 msleep(delay);
858         return delay;
859 }
860
861 static int hub_hub_status(struct usb_hub *hub,
862                 u16 *status, u16 *change)
863 {
864         int ret;
865
866         mutex_lock(&hub->status_mutex);
867         ret = get_hub_status(hub->hdev, &hub->status->hub);
868         if (ret < 0)
869                 dev_err (hub->intfdev,
870                         "%s failed (err = %d)\n", __func__, ret);
871         else {
872                 *status = le16_to_cpu(hub->status->hub.wHubStatus);
873                 *change = le16_to_cpu(hub->status->hub.wHubChange); 
874                 ret = 0;
875         }
876         mutex_unlock(&hub->status_mutex);
877         return ret;
878 }
879
880 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
881                         unsigned int link_status)
882 {
883         return set_port_feature(hub->hdev,
884                         port1 | (link_status << 3),
885                         USB_PORT_FEAT_LINK_STATE);
886 }
887
888 /*
889  * If USB 3.0 ports are placed into the Disabled state, they will no longer
890  * detect any device connects or disconnects.  This is generally not what the
891  * USB core wants, since it expects a disabled port to produce a port status
892  * change event when a new device connects.
893  *
894  * Instead, set the link state to Disabled, wait for the link to settle into
895  * that state, clear any change bits, and then put the port into the RxDetect
896  * state.
897  */
898 static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
899 {
900         int ret;
901         int total_time;
902         u16 portchange, portstatus;
903
904         if (!hub_is_superspeed(hub->hdev))
905                 return -EINVAL;
906
907         ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
908         if (ret) {
909                 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
910                                 port1, ret);
911                 return ret;
912         }
913
914         /* Wait for the link to enter the disabled state. */
915         for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
916                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
917                 if (ret < 0)
918                         return ret;
919
920                 if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
921                                 USB_SS_PORT_LS_SS_DISABLED)
922                         break;
923                 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
924                         break;
925                 msleep(HUB_DEBOUNCE_STEP);
926         }
927         if (total_time >= HUB_DEBOUNCE_TIMEOUT)
928                 dev_warn(hub->intfdev, "Could not disable port %d after %d ms\n",
929                                 port1, total_time);
930
931         return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
932 }
933
934 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
935 {
936         struct usb_device *hdev = hub->hdev;
937         int ret = 0;
938
939         if (hub->ports[port1 - 1]->child && set_state)
940                 usb_set_device_state(hub->ports[port1 - 1]->child,
941                                 USB_STATE_NOTATTACHED);
942         if (!hub->error) {
943                 if (hub_is_superspeed(hub->hdev))
944                         ret = hub_usb3_port_disable(hub, port1);
945                 else
946                         ret = clear_port_feature(hdev, port1,
947                                         USB_PORT_FEAT_ENABLE);
948         }
949         if (ret)
950                 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
951                                 port1, ret);
952         return ret;
953 }
954
955 /*
956  * Disable a port and mark a logical connect-change event, so that some
957  * time later khubd will disconnect() any existing usb_device on the port
958  * and will re-enumerate if there actually is a device attached.
959  */
960 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
961 {
962         dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
963         hub_port_disable(hub, port1, 1);
964
965         /* FIXME let caller ask to power down the port:
966          *  - some devices won't enumerate without a VBUS power cycle
967          *  - SRP saves power that way
968          *  - ... new call, TBD ...
969          * That's easy if this hub can switch power per-port, and
970          * khubd reactivates the port later (timer, SRP, etc).
971          * Powerdown must be optional, because of reset/DFU.
972          */
973
974         set_bit(port1, hub->change_bits);
975         kick_khubd(hub);
976 }
977
978 /**
979  * usb_remove_device - disable a device's port on its parent hub
980  * @udev: device to be disabled and removed
981  * Context: @udev locked, must be able to sleep.
982  *
983  * After @udev's port has been disabled, khubd is notified and it will
984  * see that the device has been disconnected.  When the device is
985  * physically unplugged and something is plugged in, the events will
986  * be received and processed normally.
987  */
988 int usb_remove_device(struct usb_device *udev)
989 {
990         struct usb_hub *hub;
991         struct usb_interface *intf;
992
993         if (!udev->parent)      /* Can't remove a root hub */
994                 return -EINVAL;
995         hub = hdev_to_hub(udev->parent);
996         intf = to_usb_interface(hub->intfdev);
997
998         usb_autopm_get_interface(intf);
999         set_bit(udev->portnum, hub->removed_bits);
1000         hub_port_logical_disconnect(hub, udev->portnum);
1001         usb_autopm_put_interface(intf);
1002         return 0;
1003 }
1004
1005 enum hub_activation_type {
1006         HUB_INIT, HUB_INIT2, HUB_INIT3,         /* INITs must come first */
1007         HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
1008 };
1009
1010 static void hub_init_func2(struct work_struct *ws);
1011 static void hub_init_func3(struct work_struct *ws);
1012
1013 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
1014 {
1015         struct usb_device *hdev = hub->hdev;
1016         struct usb_hcd *hcd;
1017         int ret;
1018         int port1;
1019         int status;
1020         bool need_debounce_delay = false;
1021         unsigned delay;
1022
1023         /* Continue a partial initialization */
1024         if (type == HUB_INIT2)
1025                 goto init2;
1026         if (type == HUB_INIT3)
1027                 goto init3;
1028
1029         /* The superspeed hub except for root hub has to use Hub Depth
1030          * value as an offset into the route string to locate the bits
1031          * it uses to determine the downstream port number. So hub driver
1032          * should send a set hub depth request to superspeed hub after
1033          * the superspeed hub is set configuration in initialization or
1034          * reset procedure.
1035          *
1036          * After a resume, port power should still be on.
1037          * For any other type of activation, turn it on.
1038          */
1039         if (type != HUB_RESUME) {
1040                 if (hdev->parent && hub_is_superspeed(hdev)) {
1041                         ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1042                                         HUB_SET_DEPTH, USB_RT_HUB,
1043                                         hdev->level - 1, 0, NULL, 0,
1044                                         USB_CTRL_SET_TIMEOUT);
1045                         if (ret < 0)
1046                                 dev_err(hub->intfdev,
1047                                                 "set hub depth failed\n");
1048                 }
1049
1050                 /* Speed up system boot by using a delayed_work for the
1051                  * hub's initial power-up delays.  This is pretty awkward
1052                  * and the implementation looks like a home-brewed sort of
1053                  * setjmp/longjmp, but it saves at least 100 ms for each
1054                  * root hub (assuming usbcore is compiled into the kernel
1055                  * rather than as a module).  It adds up.
1056                  *
1057                  * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1058                  * because for those activation types the ports have to be
1059                  * operational when we return.  In theory this could be done
1060                  * for HUB_POST_RESET, but it's easier not to.
1061                  */
1062                 if (type == HUB_INIT) {
1063                         delay = hub_power_on(hub, false);
1064                         PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
1065                         schedule_delayed_work(&hub->init_work,
1066                                         msecs_to_jiffies(delay));
1067
1068                         /* Suppress autosuspend until init is done */
1069                         usb_autopm_get_interface_no_resume(
1070                                         to_usb_interface(hub->intfdev));
1071                         return;         /* Continues at init2: below */
1072                 } else if (type == HUB_RESET_RESUME) {
1073                         /* The internal host controller state for the hub device
1074                          * may be gone after a host power loss on system resume.
1075                          * Update the device's info so the HW knows it's a hub.
1076                          */
1077                         hcd = bus_to_hcd(hdev->bus);
1078                         if (hcd->driver->update_hub_device) {
1079                                 ret = hcd->driver->update_hub_device(hcd, hdev,
1080                                                 &hub->tt, GFP_NOIO);
1081                                 if (ret < 0) {
1082                                         dev_err(hub->intfdev, "Host not "
1083                                                         "accepting hub info "
1084                                                         "update.\n");
1085                                         dev_err(hub->intfdev, "LS/FS devices "
1086                                                         "and hubs may not work "
1087                                                         "under this hub\n.");
1088                                 }
1089                         }
1090                         hub_power_on(hub, true);
1091                 } else {
1092                         hub_power_on(hub, true);
1093                 }
1094         }
1095  init2:
1096
1097         /* Check each port and set hub->change_bits to let khubd know
1098          * which ports need attention.
1099          */
1100         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1101                 struct usb_device *udev = hub->ports[port1 - 1]->child;
1102                 u16 portstatus, portchange;
1103
1104                 portstatus = portchange = 0;
1105                 status = hub_port_status(hub, port1, &portstatus, &portchange);
1106                 if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1107                         dev_dbg(hub->intfdev,
1108                                         "port %d: status %04x change %04x\n",
1109                                         port1, portstatus, portchange);
1110
1111                 /* After anything other than HUB_RESUME (i.e., initialization
1112                  * or any sort of reset), every port should be disabled.
1113                  * Unconnected ports should likewise be disabled (paranoia),
1114                  * and so should ports for which we have no usb_device.
1115                  */
1116                 if ((portstatus & USB_PORT_STAT_ENABLE) && (
1117                                 type != HUB_RESUME ||
1118                                 !(portstatus & USB_PORT_STAT_CONNECTION) ||
1119                                 !udev ||
1120                                 udev->state == USB_STATE_NOTATTACHED)) {
1121                         /*
1122                          * USB3 protocol ports will automatically transition
1123                          * to Enabled state when detect an USB3.0 device attach.
1124                          * Do not disable USB3 protocol ports.
1125                          */
1126                         if (!hub_is_superspeed(hdev)) {
1127                                 clear_port_feature(hdev, port1,
1128                                                    USB_PORT_FEAT_ENABLE);
1129                                 portstatus &= ~USB_PORT_STAT_ENABLE;
1130                         } else {
1131                                 /* Pretend that power was lost for USB3 devs */
1132                                 portstatus &= ~USB_PORT_STAT_ENABLE;
1133                         }
1134                 }
1135
1136                 /* Clear status-change flags; we'll debounce later */
1137                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
1138                         need_debounce_delay = true;
1139                         clear_port_feature(hub->hdev, port1,
1140                                         USB_PORT_FEAT_C_CONNECTION);
1141                 }
1142                 if (portchange & USB_PORT_STAT_C_ENABLE) {
1143                         need_debounce_delay = true;
1144                         clear_port_feature(hub->hdev, port1,
1145                                         USB_PORT_FEAT_C_ENABLE);
1146                 }
1147                 if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1148                                 hub_is_superspeed(hub->hdev)) {
1149                         need_debounce_delay = true;
1150                         clear_port_feature(hub->hdev, port1,
1151                                         USB_PORT_FEAT_C_BH_PORT_RESET);
1152                 }
1153                 /* We can forget about a "removed" device when there's a
1154                  * physical disconnect or the connect status changes.
1155                  */
1156                 if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1157                                 (portchange & USB_PORT_STAT_C_CONNECTION))
1158                         clear_bit(port1, hub->removed_bits);
1159
1160                 if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1161                         /* Tell khubd to disconnect the device or
1162                          * check for a new connection
1163                          */
1164                         if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1165                                 set_bit(port1, hub->change_bits);
1166
1167                 } else if (portstatus & USB_PORT_STAT_ENABLE) {
1168                         bool port_resumed = (portstatus &
1169                                         USB_PORT_STAT_LINK_STATE) ==
1170                                 USB_SS_PORT_LS_U0;
1171                         /* The power session apparently survived the resume.
1172                          * If there was an overcurrent or suspend change
1173                          * (i.e., remote wakeup request), have khubd
1174                          * take care of it.  Look at the port link state
1175                          * for USB 3.0 hubs, since they don't have a suspend
1176                          * change bit, and they don't set the port link change
1177                          * bit on device-initiated resume.
1178                          */
1179                         if (portchange || (hub_is_superspeed(hub->hdev) &&
1180                                                 port_resumed))
1181                                 set_bit(port1, hub->change_bits);
1182
1183                 } else if (udev->persist_enabled) {
1184 #ifdef CONFIG_PM
1185                         udev->reset_resume = 1;
1186 #endif
1187                         set_bit(port1, hub->change_bits);
1188
1189                 } else {
1190                         /* The power session is gone; tell khubd */
1191                         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1192                         set_bit(port1, hub->change_bits);
1193                 }
1194         }
1195
1196         /* If no port-status-change flags were set, we don't need any
1197          * debouncing.  If flags were set we can try to debounce the
1198          * ports all at once right now, instead of letting khubd do them
1199          * one at a time later on.
1200          *
1201          * If any port-status changes do occur during this delay, khubd
1202          * will see them later and handle them normally.
1203          */
1204         if (need_debounce_delay) {
1205                 delay = HUB_DEBOUNCE_STABLE;
1206
1207                 /* Don't do a long sleep inside a workqueue routine */
1208                 if (type == HUB_INIT2) {
1209                         PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
1210                         schedule_delayed_work(&hub->init_work,
1211                                         msecs_to_jiffies(delay));
1212                         return;         /* Continues at init3: below */
1213                 } else {
1214                         msleep(delay);
1215                 }
1216         }
1217  init3:
1218         hub->quiescing = 0;
1219
1220         status = usb_submit_urb(hub->urb, GFP_NOIO);
1221         if (status < 0)
1222                 dev_err(hub->intfdev, "activate --> %d\n", status);
1223         if (hub->has_indicators && blinkenlights)
1224                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
1225
1226         /* Scan all ports that need attention */
1227         kick_khubd(hub);
1228
1229         /* Allow autosuspend if it was suppressed */
1230         if (type <= HUB_INIT3)
1231                 usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1232 }
1233
1234 /* Implement the continuations for the delays above */
1235 static void hub_init_func2(struct work_struct *ws)
1236 {
1237         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1238
1239         hub_activate(hub, HUB_INIT2);
1240 }
1241
1242 static void hub_init_func3(struct work_struct *ws)
1243 {
1244         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1245
1246         hub_activate(hub, HUB_INIT3);
1247 }
1248
1249 enum hub_quiescing_type {
1250         HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1251 };
1252
1253 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1254 {
1255         struct usb_device *hdev = hub->hdev;
1256         int i;
1257
1258         cancel_delayed_work_sync(&hub->init_work);
1259
1260         /* khubd and related activity won't re-trigger */
1261         hub->quiescing = 1;
1262
1263         if (type != HUB_SUSPEND) {
1264                 /* Disconnect all the children */
1265                 for (i = 0; i < hdev->maxchild; ++i) {
1266                         if (hub->ports[i]->child)
1267                                 usb_disconnect(&hub->ports[i]->child);
1268                 }
1269         }
1270
1271         /* Stop khubd and related activity */
1272         usb_kill_urb(hub->urb);
1273         if (hub->has_indicators)
1274                 cancel_delayed_work_sync(&hub->leds);
1275         if (hub->tt.hub)
1276                 flush_work(&hub->tt.clear_work);
1277 }
1278
1279 /* caller has locked the hub device */
1280 static int hub_pre_reset(struct usb_interface *intf)
1281 {
1282         struct usb_hub *hub = usb_get_intfdata(intf);
1283
1284         hub_quiesce(hub, HUB_PRE_RESET);
1285         return 0;
1286 }
1287
1288 /* caller has locked the hub device */
1289 static int hub_post_reset(struct usb_interface *intf)
1290 {
1291         struct usb_hub *hub = usb_get_intfdata(intf);
1292
1293         hub_activate(hub, HUB_POST_RESET);
1294         return 0;
1295 }
1296
1297 static void usb_port_device_release(struct device *dev)
1298 {
1299         struct usb_port *port_dev = to_usb_port(dev);
1300
1301         kfree(port_dev);
1302 }
1303
1304 static void usb_hub_remove_port_device(struct usb_hub *hub,
1305                                        int port1)
1306 {
1307         device_unregister(&hub->ports[port1 - 1]->dev);
1308 }
1309
1310 struct device_type usb_port_device_type = {
1311         .name =         "usb_port",
1312         .release =      usb_port_device_release,
1313 };
1314
1315 static int usb_hub_create_port_device(struct usb_hub *hub,
1316                                       int port1)
1317 {
1318         struct usb_port *port_dev = NULL;
1319         int retval;
1320
1321         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
1322         if (!port_dev) {
1323                 retval = -ENOMEM;
1324                 goto exit;
1325         }
1326
1327         hub->ports[port1 - 1] = port_dev;
1328         port_dev->dev.parent = hub->intfdev;
1329         port_dev->dev.type = &usb_port_device_type;
1330         dev_set_name(&port_dev->dev, "port%d", port1);
1331
1332         retval = device_register(&port_dev->dev);
1333         if (retval)
1334                 goto error_register;
1335         return 0;
1336
1337 error_register:
1338         put_device(&port_dev->dev);
1339 exit:
1340         return retval;
1341 }
1342
1343 static int hub_configure(struct usb_hub *hub,
1344         struct usb_endpoint_descriptor *endpoint)
1345 {
1346         struct usb_hcd *hcd;
1347         struct usb_device *hdev = hub->hdev;
1348         struct device *hub_dev = hub->intfdev;
1349         u16 hubstatus, hubchange;
1350         u16 wHubCharacteristics;
1351         unsigned int pipe;
1352         int maxp, ret, i;
1353         char *message = "out of memory";
1354
1355         hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1356         if (!hub->buffer) {
1357                 ret = -ENOMEM;
1358                 goto fail;
1359         }
1360
1361         hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1362         if (!hub->status) {
1363                 ret = -ENOMEM;
1364                 goto fail;
1365         }
1366         mutex_init(&hub->status_mutex);
1367
1368         hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1369         if (!hub->descriptor) {
1370                 ret = -ENOMEM;
1371                 goto fail;
1372         }
1373
1374         /* Request the entire hub descriptor.
1375          * hub->descriptor can handle USB_MAXCHILDREN ports,
1376          * but the hub can/will return fewer bytes here.
1377          */
1378         ret = get_hub_descriptor(hdev, hub->descriptor);
1379         if (ret < 0) {
1380                 message = "can't read hub descriptor";
1381                 goto fail;
1382         } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
1383                 message = "hub has too many ports!";
1384                 ret = -ENODEV;
1385                 goto fail;
1386         }
1387
1388         hdev->maxchild = hub->descriptor->bNbrPorts;
1389         dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
1390                 (hdev->maxchild == 1) ? "" : "s");
1391
1392         hub->ports = kzalloc(hdev->maxchild * sizeof(struct usb_port *),
1393                              GFP_KERNEL);
1394         if (!hub->ports) {
1395                 ret = -ENOMEM;
1396                 goto fail;
1397         }
1398
1399         wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1400
1401         /* FIXME for USB 3.0, skip for now */
1402         if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1403                         !(hub_is_superspeed(hdev))) {
1404                 int     i;
1405                 char    portstr [USB_MAXCHILDREN + 1];
1406
1407                 for (i = 0; i < hdev->maxchild; i++)
1408                         portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1409                                     [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1410                                 ? 'F' : 'R';
1411                 portstr[hdev->maxchild] = 0;
1412                 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1413         } else
1414                 dev_dbg(hub_dev, "standalone hub\n");
1415
1416         switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1417         case HUB_CHAR_COMMON_LPSM:
1418                 dev_dbg(hub_dev, "ganged power switching\n");
1419                 break;
1420         case HUB_CHAR_INDV_PORT_LPSM:
1421                 dev_dbg(hub_dev, "individual port power switching\n");
1422                 break;
1423         case HUB_CHAR_NO_LPSM:
1424         case HUB_CHAR_LPSM:
1425                 dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1426                 break;
1427         }
1428
1429         switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1430         case HUB_CHAR_COMMON_OCPM:
1431                 dev_dbg(hub_dev, "global over-current protection\n");
1432                 break;
1433         case HUB_CHAR_INDV_PORT_OCPM:
1434                 dev_dbg(hub_dev, "individual port over-current protection\n");
1435                 break;
1436         case HUB_CHAR_NO_OCPM:
1437         case HUB_CHAR_OCPM:
1438                 dev_dbg(hub_dev, "no over-current protection\n");
1439                 break;
1440         }
1441
1442         spin_lock_init (&hub->tt.lock);
1443         INIT_LIST_HEAD (&hub->tt.clear_list);
1444         INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1445         switch (hdev->descriptor.bDeviceProtocol) {
1446         case USB_HUB_PR_FS:
1447                 break;
1448         case USB_HUB_PR_HS_SINGLE_TT:
1449                 dev_dbg(hub_dev, "Single TT\n");
1450                 hub->tt.hub = hdev;
1451                 break;
1452         case USB_HUB_PR_HS_MULTI_TT:
1453                 ret = usb_set_interface(hdev, 0, 1);
1454                 if (ret == 0) {
1455                         dev_dbg(hub_dev, "TT per port\n");
1456                         hub->tt.multi = 1;
1457                 } else
1458                         dev_err(hub_dev, "Using single TT (err %d)\n",
1459                                 ret);
1460                 hub->tt.hub = hdev;
1461                 break;
1462         case USB_HUB_PR_SS:
1463                 /* USB 3.0 hubs don't have a TT */
1464                 break;
1465         default:
1466                 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1467                         hdev->descriptor.bDeviceProtocol);
1468                 break;
1469         }
1470
1471         /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1472         switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1473                 case HUB_TTTT_8_BITS:
1474                         if (hdev->descriptor.bDeviceProtocol != 0) {
1475                                 hub->tt.think_time = 666;
1476                                 dev_dbg(hub_dev, "TT requires at most %d "
1477                                                 "FS bit times (%d ns)\n",
1478                                         8, hub->tt.think_time);
1479                         }
1480                         break;
1481                 case HUB_TTTT_16_BITS:
1482                         hub->tt.think_time = 666 * 2;
1483                         dev_dbg(hub_dev, "TT requires at most %d "
1484                                         "FS bit times (%d ns)\n",
1485                                 16, hub->tt.think_time);
1486                         break;
1487                 case HUB_TTTT_24_BITS:
1488                         hub->tt.think_time = 666 * 3;
1489                         dev_dbg(hub_dev, "TT requires at most %d "
1490                                         "FS bit times (%d ns)\n",
1491                                 24, hub->tt.think_time);
1492                         break;
1493                 case HUB_TTTT_32_BITS:
1494                         hub->tt.think_time = 666 * 4;
1495                         dev_dbg(hub_dev, "TT requires at most %d "
1496                                         "FS bit times (%d ns)\n",
1497                                 32, hub->tt.think_time);
1498                         break;
1499         }
1500
1501         /* probe() zeroes hub->indicator[] */
1502         if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1503                 hub->has_indicators = 1;
1504                 dev_dbg(hub_dev, "Port indicators are supported\n");
1505         }
1506
1507         dev_dbg(hub_dev, "power on to power good time: %dms\n",
1508                 hub->descriptor->bPwrOn2PwrGood * 2);
1509
1510         /* power budgeting mostly matters with bus-powered hubs,
1511          * and battery-powered root hubs (may provide just 8 mA).
1512          */
1513         ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1514         if (ret < 2) {
1515                 message = "can't get hub status";
1516                 goto fail;
1517         }
1518         le16_to_cpus(&hubstatus);
1519         if (hdev == hdev->bus->root_hub) {
1520                 if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
1521                         hub->mA_per_port = 500;
1522                 else {
1523                         hub->mA_per_port = hdev->bus_mA;
1524                         hub->limited_power = 1;
1525                 }
1526         } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1527                 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1528                         hub->descriptor->bHubContrCurrent);
1529                 hub->limited_power = 1;
1530                 if (hdev->maxchild > 0) {
1531                         int remaining = hdev->bus_mA -
1532                                         hub->descriptor->bHubContrCurrent;
1533
1534                         if (remaining < hdev->maxchild * 100)
1535                                 dev_warn(hub_dev,
1536                                         "insufficient power available "
1537                                         "to use all downstream ports\n");
1538                         hub->mA_per_port = 100;         /* 7.2.1.1 */
1539                 }
1540         } else {        /* Self-powered external hub */
1541                 /* FIXME: What about battery-powered external hubs that
1542                  * provide less current per port? */
1543                 hub->mA_per_port = 500;
1544         }
1545         if (hub->mA_per_port < 500)
1546                 dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1547                                 hub->mA_per_port);
1548
1549         /* Update the HCD's internal representation of this hub before khubd
1550          * starts getting port status changes for devices under the hub.
1551          */
1552         hcd = bus_to_hcd(hdev->bus);
1553         if (hcd->driver->update_hub_device) {
1554                 ret = hcd->driver->update_hub_device(hcd, hdev,
1555                                 &hub->tt, GFP_KERNEL);
1556                 if (ret < 0) {
1557                         message = "can't update HCD hub info";
1558                         goto fail;
1559                 }
1560         }
1561
1562         ret = hub_hub_status(hub, &hubstatus, &hubchange);
1563         if (ret < 0) {
1564                 message = "can't get hub status";
1565                 goto fail;
1566         }
1567
1568         /* local power status reports aren't always correct */
1569         if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1570                 dev_dbg(hub_dev, "local power source is %s\n",
1571                         (hubstatus & HUB_STATUS_LOCAL_POWER)
1572                         ? "lost (inactive)" : "good");
1573
1574         if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1575                 dev_dbg(hub_dev, "%sover-current condition exists\n",
1576                         (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1577
1578         /* set up the interrupt endpoint
1579          * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1580          * bytes as USB2.0[11.12.3] says because some hubs are known
1581          * to send more data (and thus cause overflow). For root hubs,
1582          * maxpktsize is defined in hcd.c's fake endpoint descriptors
1583          * to be big enough for at least USB_MAXCHILDREN ports. */
1584         pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1585         maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1586
1587         if (maxp > sizeof(*hub->buffer))
1588                 maxp = sizeof(*hub->buffer);
1589
1590         hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1591         if (!hub->urb) {
1592                 ret = -ENOMEM;
1593                 goto fail;
1594         }
1595
1596         usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1597                 hub, endpoint->bInterval);
1598
1599         /* maybe cycle the hub leds */
1600         if (hub->has_indicators && blinkenlights)
1601                 hub->indicator [0] = INDICATOR_CYCLE;
1602
1603         for (i = 0; i < hdev->maxchild; i++)
1604                 if (usb_hub_create_port_device(hub, i + 1) < 0)
1605                         dev_err(hub->intfdev,
1606                                 "couldn't create port%d device.\n", i + 1);
1607
1608         hub_activate(hub, HUB_INIT);
1609         return 0;
1610
1611 fail:
1612         dev_err (hub_dev, "config failed, %s (err %d)\n",
1613                         message, ret);
1614         /* hub_disconnect() frees urb and descriptor */
1615         return ret;
1616 }
1617
1618 static void hub_release(struct kref *kref)
1619 {
1620         struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1621
1622         usb_put_intf(to_usb_interface(hub->intfdev));
1623         kfree(hub);
1624 }
1625
1626 static unsigned highspeed_hubs;
1627
1628 static void hub_disconnect(struct usb_interface *intf)
1629 {
1630         struct usb_hub *hub = usb_get_intfdata(intf);
1631         struct usb_device *hdev = interface_to_usbdev(intf);
1632         int i;
1633
1634         /* Take the hub off the event list and don't let it be added again */
1635         spin_lock_irq(&hub_event_lock);
1636         if (!list_empty(&hub->event_list)) {
1637                 list_del_init(&hub->event_list);
1638                 usb_autopm_put_interface_no_suspend(intf);
1639         }
1640         hub->disconnected = 1;
1641         spin_unlock_irq(&hub_event_lock);
1642
1643         /* Disconnect all children and quiesce the hub */
1644         hub->error = 0;
1645         hub_quiesce(hub, HUB_DISCONNECT);
1646
1647         usb_set_intfdata (intf, NULL);
1648
1649         for (i = 0; i < hdev->maxchild; i++)
1650                 usb_hub_remove_port_device(hub, i + 1);
1651         hub->hdev->maxchild = 0;
1652
1653         if (hub->hdev->speed == USB_SPEED_HIGH)
1654                 highspeed_hubs--;
1655
1656         usb_free_urb(hub->urb);
1657         kfree(hub->ports);
1658         kfree(hub->descriptor);
1659         kfree(hub->status);
1660         kfree(hub->buffer);
1661
1662         kref_put(&hub->kref, hub_release);
1663 }
1664
1665 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1666 {
1667         struct usb_host_interface *desc;
1668         struct usb_endpoint_descriptor *endpoint;
1669         struct usb_device *hdev;
1670         struct usb_hub *hub;
1671
1672         desc = intf->cur_altsetting;
1673         hdev = interface_to_usbdev(intf);
1674
1675         /*
1676          * Set default autosuspend delay as 0 to speedup bus suspend,
1677          * based on the below considerations:
1678          *
1679          * - Unlike other drivers, the hub driver does not rely on the
1680          *   autosuspend delay to provide enough time to handle a wakeup
1681          *   event, and the submitted status URB is just to check future
1682          *   change on hub downstream ports, so it is safe to do it.
1683          *
1684          * - The patch might cause one or more auto supend/resume for
1685          *   below very rare devices when they are plugged into hub
1686          *   first time:
1687          *
1688          *      devices having trouble initializing, and disconnect
1689          *      themselves from the bus and then reconnect a second
1690          *      or so later
1691          *
1692          *      devices just for downloading firmware, and disconnects
1693          *      themselves after completing it
1694          *
1695          *   For these quite rare devices, their drivers may change the
1696          *   autosuspend delay of their parent hub in the probe() to one
1697          *   appropriate value to avoid the subtle problem if someone
1698          *   does care it.
1699          *
1700          * - The patch may cause one or more auto suspend/resume on
1701          *   hub during running 'lsusb', but it is probably too
1702          *   infrequent to worry about.
1703          *
1704          * - Change autosuspend delay of hub can avoid unnecessary auto
1705          *   suspend timer for hub, also may decrease power consumption
1706          *   of USB bus.
1707          */
1708         pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1709
1710         /* Hubs have proper suspend/resume support. */
1711         usb_enable_autosuspend(hdev);
1712
1713         if (hdev->level == MAX_TOPO_LEVEL) {
1714                 dev_err(&intf->dev,
1715                         "Unsupported bus topology: hub nested too deep\n");
1716                 return -E2BIG;
1717         }
1718
1719 #ifdef  CONFIG_USB_OTG_BLACKLIST_HUB
1720         if (hdev->parent) {
1721                 dev_warn(&intf->dev, "ignoring external hub\n");
1722                 return -ENODEV;
1723         }
1724 #endif
1725
1726         /* Some hubs have a subclass of 1, which AFAICT according to the */
1727         /*  specs is not defined, but it works */
1728         if ((desc->desc.bInterfaceSubClass != 0) &&
1729             (desc->desc.bInterfaceSubClass != 1)) {
1730 descriptor_error:
1731                 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1732                 return -EIO;
1733         }
1734
1735         /* Multiple endpoints? What kind of mutant ninja-hub is this? */
1736         if (desc->desc.bNumEndpoints != 1)
1737                 goto descriptor_error;
1738
1739         endpoint = &desc->endpoint[0].desc;
1740
1741         /* If it's not an interrupt in endpoint, we'd better punt! */
1742         if (!usb_endpoint_is_int_in(endpoint))
1743                 goto descriptor_error;
1744
1745         /* We found a hub */
1746         dev_info (&intf->dev, "USB hub found\n");
1747
1748         hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1749         if (!hub) {
1750                 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1751                 return -ENOMEM;
1752         }
1753
1754         kref_init(&hub->kref);
1755         INIT_LIST_HEAD(&hub->event_list);
1756         hub->intfdev = &intf->dev;
1757         hub->hdev = hdev;
1758         INIT_DELAYED_WORK(&hub->leds, led_work);
1759         INIT_DELAYED_WORK(&hub->init_work, NULL);
1760         usb_get_intf(intf);
1761
1762         usb_set_intfdata (intf, hub);
1763         intf->needs_remote_wakeup = 1;
1764
1765         if (hdev->speed == USB_SPEED_HIGH)
1766                 highspeed_hubs++;
1767
1768         if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1769                 hub->quirk_check_port_auto_suspend = 1;
1770
1771         if (hub_configure(hub, endpoint) >= 0)
1772                 return 0;
1773
1774         hub_disconnect (intf);
1775         return -ENODEV;
1776 }
1777
1778 static int
1779 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1780 {
1781         struct usb_device *hdev = interface_to_usbdev (intf);
1782         struct usb_hub *hub = hdev_to_hub(hdev);
1783
1784         /* assert ifno == 0 (part of hub spec) */
1785         switch (code) {
1786         case USBDEVFS_HUB_PORTINFO: {
1787                 struct usbdevfs_hub_portinfo *info = user_data;
1788                 int i;
1789
1790                 spin_lock_irq(&device_state_lock);
1791                 if (hdev->devnum <= 0)
1792                         info->nports = 0;
1793                 else {
1794                         info->nports = hdev->maxchild;
1795                         for (i = 0; i < info->nports; i++) {
1796                                 if (hub->ports[i]->child == NULL)
1797                                         info->port[i] = 0;
1798                                 else
1799                                         info->port[i] =
1800                                                 hub->ports[i]->child->devnum;
1801                         }
1802                 }
1803                 spin_unlock_irq(&device_state_lock);
1804
1805                 return info->nports + 1;
1806                 }
1807
1808         default:
1809                 return -ENOSYS;
1810         }
1811 }
1812
1813 /*
1814  * Allow user programs to claim ports on a hub.  When a device is attached
1815  * to one of these "claimed" ports, the program will "own" the device.
1816  */
1817 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1818                 struct dev_state ***ppowner)
1819 {
1820         if (hdev->state == USB_STATE_NOTATTACHED)
1821                 return -ENODEV;
1822         if (port1 == 0 || port1 > hdev->maxchild)
1823                 return -EINVAL;
1824
1825         /* This assumes that devices not managed by the hub driver
1826          * will always have maxchild equal to 0.
1827          */
1828         *ppowner = &(hdev_to_hub(hdev)->ports[port1 - 1]->port_owner);
1829         return 0;
1830 }
1831
1832 /* In the following three functions, the caller must hold hdev's lock */
1833 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1834                        struct dev_state *owner)
1835 {
1836         int rc;
1837         struct dev_state **powner;
1838
1839         rc = find_port_owner(hdev, port1, &powner);
1840         if (rc)
1841                 return rc;
1842         if (*powner)
1843                 return -EBUSY;
1844         *powner = owner;
1845         return rc;
1846 }
1847
1848 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
1849                          struct dev_state *owner)
1850 {
1851         int rc;
1852         struct dev_state **powner;
1853
1854         rc = find_port_owner(hdev, port1, &powner);
1855         if (rc)
1856                 return rc;
1857         if (*powner != owner)
1858                 return -ENOENT;
1859         *powner = NULL;
1860         return rc;
1861 }
1862
1863 void usb_hub_release_all_ports(struct usb_device *hdev, struct dev_state *owner)
1864 {
1865         struct usb_hub *hub = hdev_to_hub(hdev);
1866         int n;
1867
1868         for (n = 0; n < hdev->maxchild; n++) {
1869                 if (hub->ports[n]->port_owner == owner)
1870                         hub->ports[n]->port_owner = NULL;
1871         }
1872
1873 }
1874
1875 /* The caller must hold udev's lock */
1876 bool usb_device_is_owned(struct usb_device *udev)
1877 {
1878         struct usb_hub *hub;
1879
1880         if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1881                 return false;
1882         hub = hdev_to_hub(udev->parent);
1883         return !!hub->ports[udev->portnum - 1]->port_owner;
1884 }
1885
1886 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1887 {
1888         struct usb_hub *hub = hdev_to_hub(udev);
1889         int i;
1890
1891         for (i = 0; i < udev->maxchild; ++i) {
1892                 if (hub->ports[i]->child)
1893                         recursively_mark_NOTATTACHED(hub->ports[i]->child);
1894         }
1895         if (udev->state == USB_STATE_SUSPENDED)
1896                 udev->active_duration -= jiffies;
1897         udev->state = USB_STATE_NOTATTACHED;
1898 }
1899
1900 /**
1901  * usb_set_device_state - change a device's current state (usbcore, hcds)
1902  * @udev: pointer to device whose state should be changed
1903  * @new_state: new state value to be stored
1904  *
1905  * udev->state is _not_ fully protected by the device lock.  Although
1906  * most transitions are made only while holding the lock, the state can
1907  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1908  * is so that devices can be marked as disconnected as soon as possible,
1909  * without having to wait for any semaphores to be released.  As a result,
1910  * all changes to any device's state must be protected by the
1911  * device_state_lock spinlock.
1912  *
1913  * Once a device has been added to the device tree, all changes to its state
1914  * should be made using this routine.  The state should _not_ be set directly.
1915  *
1916  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1917  * Otherwise udev->state is set to new_state, and if new_state is
1918  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1919  * to USB_STATE_NOTATTACHED.
1920  */
1921 void usb_set_device_state(struct usb_device *udev,
1922                 enum usb_device_state new_state)
1923 {
1924         unsigned long flags;
1925         int wakeup = -1;
1926
1927         spin_lock_irqsave(&device_state_lock, flags);
1928         if (udev->state == USB_STATE_NOTATTACHED)
1929                 ;       /* do nothing */
1930         else if (new_state != USB_STATE_NOTATTACHED) {
1931
1932                 /* root hub wakeup capabilities are managed out-of-band
1933                  * and may involve silicon errata ... ignore them here.
1934                  */
1935                 if (udev->parent) {
1936                         if (udev->state == USB_STATE_SUSPENDED
1937                                         || new_state == USB_STATE_SUSPENDED)
1938                                 ;       /* No change to wakeup settings */
1939                         else if (new_state == USB_STATE_CONFIGURED)
1940                                 wakeup = udev->actconfig->desc.bmAttributes
1941                                          & USB_CONFIG_ATT_WAKEUP;
1942                         else
1943                                 wakeup = 0;
1944                 }
1945                 if (udev->state == USB_STATE_SUSPENDED &&
1946                         new_state != USB_STATE_SUSPENDED)
1947                         udev->active_duration -= jiffies;
1948                 else if (new_state == USB_STATE_SUSPENDED &&
1949                                 udev->state != USB_STATE_SUSPENDED)
1950                         udev->active_duration += jiffies;
1951                 udev->state = new_state;
1952         } else
1953                 recursively_mark_NOTATTACHED(udev);
1954         spin_unlock_irqrestore(&device_state_lock, flags);
1955         if (wakeup >= 0)
1956                 device_set_wakeup_capable(&udev->dev, wakeup);
1957 }
1958 EXPORT_SYMBOL_GPL(usb_set_device_state);
1959
1960 /*
1961  * Choose a device number.
1962  *
1963  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
1964  * USB-2.0 buses they are also used as device addresses, however on
1965  * USB-3.0 buses the address is assigned by the controller hardware
1966  * and it usually is not the same as the device number.
1967  *
1968  * WUSB devices are simple: they have no hubs behind, so the mapping
1969  * device <-> virtual port number becomes 1:1. Why? to simplify the
1970  * life of the device connection logic in
1971  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1972  * handshake we need to assign a temporary address in the unauthorized
1973  * space. For simplicity we use the first virtual port number found to
1974  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1975  * and that becomes it's address [X < 128] or its unauthorized address
1976  * [X | 0x80].
1977  *
1978  * We add 1 as an offset to the one-based USB-stack port number
1979  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1980  * 0 is reserved by USB for default address; (b) Linux's USB stack
1981  * uses always #1 for the root hub of the controller. So USB stack's
1982  * port #1, which is wusb virtual-port #0 has address #2.
1983  *
1984  * Devices connected under xHCI are not as simple.  The host controller
1985  * supports virtualization, so the hardware assigns device addresses and
1986  * the HCD must setup data structures before issuing a set address
1987  * command to the hardware.
1988  */
1989 static void choose_devnum(struct usb_device *udev)
1990 {
1991         int             devnum;
1992         struct usb_bus  *bus = udev->bus;
1993
1994         /* If khubd ever becomes multithreaded, this will need a lock */
1995         if (udev->wusb) {
1996                 devnum = udev->portnum + 1;
1997                 BUG_ON(test_bit(devnum, bus->devmap.devicemap));
1998         } else {
1999                 /* Try to allocate the next devnum beginning at
2000                  * bus->devnum_next. */
2001                 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2002                                             bus->devnum_next);
2003                 if (devnum >= 128)
2004                         devnum = find_next_zero_bit(bus->devmap.devicemap,
2005                                                     128, 1);
2006                 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
2007         }
2008         if (devnum < 128) {
2009                 set_bit(devnum, bus->devmap.devicemap);
2010                 udev->devnum = devnum;
2011         }
2012 }
2013
2014 static void release_devnum(struct usb_device *udev)
2015 {
2016         if (udev->devnum > 0) {
2017                 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2018                 udev->devnum = -1;
2019         }
2020 }
2021
2022 static void update_devnum(struct usb_device *udev, int devnum)
2023 {
2024         /* The address for a WUSB device is managed by wusbcore. */
2025         if (!udev->wusb)
2026                 udev->devnum = devnum;
2027 }
2028
2029 static void hub_free_dev(struct usb_device *udev)
2030 {
2031         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2032
2033         /* Root hubs aren't real devices, so don't free HCD resources */
2034         if (hcd->driver->free_dev && udev->parent)
2035                 hcd->driver->free_dev(hcd, udev);
2036 }
2037
2038 /**
2039  * usb_disconnect - disconnect a device (usbcore-internal)
2040  * @pdev: pointer to device being disconnected
2041  * Context: !in_interrupt ()
2042  *
2043  * Something got disconnected. Get rid of it and all of its children.
2044  *
2045  * If *pdev is a normal device then the parent hub must already be locked.
2046  * If *pdev is a root hub then this routine will acquire the
2047  * usb_bus_list_lock on behalf of the caller.
2048  *
2049  * Only hub drivers (including virtual root hub drivers for host
2050  * controllers) should ever call this.
2051  *
2052  * This call is synchronous, and may not be used in an interrupt context.
2053  */
2054 void usb_disconnect(struct usb_device **pdev)
2055 {
2056         struct usb_device       *udev = *pdev;
2057         struct usb_hub          *hub = hdev_to_hub(udev);
2058         int                     i;
2059
2060         /* mark the device as inactive, so any further urb submissions for
2061          * this device (and any of its children) will fail immediately.
2062          * this quiesces everything except pending urbs.
2063          */
2064         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2065         dev_info(&udev->dev, "USB disconnect, device number %d\n",
2066                         udev->devnum);
2067
2068         usb_lock_device(udev);
2069
2070         /* Free up all the children before we remove this device */
2071         for (i = 0; i < udev->maxchild; i++) {
2072                 if (hub->ports[i]->child)
2073                         usb_disconnect(&hub->ports[i]->child);
2074         }
2075
2076         /* deallocate hcd/hardware state ... nuking all pending urbs and
2077          * cleaning up all state associated with the current configuration
2078          * so that the hardware is now fully quiesced.
2079          */
2080         dev_dbg (&udev->dev, "unregistering device\n");
2081         usb_disable_device(udev, 0);
2082         usb_hcd_synchronize_unlinks(udev);
2083
2084         usb_remove_ep_devs(&udev->ep0);
2085         usb_unlock_device(udev);
2086
2087         /* Unregister the device.  The device driver is responsible
2088          * for de-configuring the device and invoking the remove-device
2089          * notifier chain (used by usbfs and possibly others).
2090          */
2091         device_del(&udev->dev);
2092
2093         /* Free the device number and delete the parent's children[]
2094          * (or root_hub) pointer.
2095          */
2096         release_devnum(udev);
2097
2098         /* Avoid races with recursively_mark_NOTATTACHED() */
2099         spin_lock_irq(&device_state_lock);
2100         *pdev = NULL;
2101         spin_unlock_irq(&device_state_lock);
2102
2103         hub_free_dev(udev);
2104
2105         put_device(&udev->dev);
2106 }
2107
2108 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
2109 static void show_string(struct usb_device *udev, char *id, char *string)
2110 {
2111         if (!string)
2112                 return;
2113         dev_info(&udev->dev, "%s: %s\n", id, string);
2114 }
2115
2116 static void announce_device(struct usb_device *udev)
2117 {
2118         dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
2119                 le16_to_cpu(udev->descriptor.idVendor),
2120                 le16_to_cpu(udev->descriptor.idProduct));
2121         dev_info(&udev->dev,
2122                 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2123                 udev->descriptor.iManufacturer,
2124                 udev->descriptor.iProduct,
2125                 udev->descriptor.iSerialNumber);
2126         show_string(udev, "Product", udev->product);
2127         show_string(udev, "Manufacturer", udev->manufacturer);
2128         show_string(udev, "SerialNumber", udev->serial);
2129 }
2130 #else
2131 static inline void announce_device(struct usb_device *udev) { }
2132 #endif
2133
2134 #ifdef  CONFIG_USB_OTG
2135 #include "otg_whitelist.h"
2136 #endif
2137
2138 /**
2139  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2140  * @udev: newly addressed device (in ADDRESS state)
2141  *
2142  * Finish enumeration for On-The-Go devices
2143  */
2144 static int usb_enumerate_device_otg(struct usb_device *udev)
2145 {
2146         int err = 0;
2147
2148 #ifdef  CONFIG_USB_OTG
2149         /*
2150          * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2151          * to wake us after we've powered off VBUS; and HNP, switching roles
2152          * "host" to "peripheral".  The OTG descriptor helps figure this out.
2153          */
2154         if (!udev->bus->is_b_host
2155                         && udev->config
2156                         && udev->parent == udev->bus->root_hub) {
2157                 struct usb_otg_descriptor       *desc = NULL;
2158                 struct usb_bus                  *bus = udev->bus;
2159
2160                 /* descriptor may appear anywhere in config */
2161                 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
2162                                         le16_to_cpu(udev->config[0].desc.wTotalLength),
2163                                         USB_DT_OTG, (void **) &desc) == 0) {
2164                         if (desc->bmAttributes & USB_OTG_HNP) {
2165                                 unsigned                port1 = udev->portnum;
2166
2167                                 dev_info(&udev->dev,
2168                                         "Dual-Role OTG device on %sHNP port\n",
2169                                         (port1 == bus->otg_port)
2170                                                 ? "" : "non-");
2171
2172                                 /* enable HNP before suspend, it's simpler */
2173                                 if (port1 == bus->otg_port)
2174                                         bus->b_hnp_enable = 1;
2175                                 err = usb_control_msg(udev,
2176                                         usb_sndctrlpipe(udev, 0),
2177                                         USB_REQ_SET_FEATURE, 0,
2178                                         bus->b_hnp_enable
2179                                                 ? USB_DEVICE_B_HNP_ENABLE
2180                                                 : USB_DEVICE_A_ALT_HNP_SUPPORT,
2181                                         0, NULL, 0, USB_CTRL_SET_TIMEOUT);
2182                                 if (err < 0) {
2183                                         /* OTG MESSAGE: report errors here,
2184                                          * customize to match your product.
2185                                          */
2186                                         dev_info(&udev->dev,
2187                                                 "can't set HNP mode: %d\n",
2188                                                 err);
2189                                         bus->b_hnp_enable = 0;
2190                                 }
2191                         }
2192                 }
2193         }
2194
2195         if (!is_targeted(udev)) {
2196
2197                 /* Maybe it can talk to us, though we can't talk to it.
2198                  * (Includes HNP test device.)
2199                  */
2200                 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
2201                         err = usb_port_suspend(udev, PMSG_SUSPEND);
2202                         if (err < 0)
2203                                 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2204                 }
2205                 err = -ENOTSUPP;
2206                 goto fail;
2207         }
2208 fail:
2209 #endif
2210         return err;
2211 }
2212
2213
2214 /**
2215  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2216  * @udev: newly addressed device (in ADDRESS state)
2217  *
2218  * This is only called by usb_new_device() and usb_authorize_device()
2219  * and FIXME -- all comments that apply to them apply here wrt to
2220  * environment.
2221  *
2222  * If the device is WUSB and not authorized, we don't attempt to read
2223  * the string descriptors, as they will be errored out by the device
2224  * until it has been authorized.
2225  */
2226 static int usb_enumerate_device(struct usb_device *udev)
2227 {
2228         int err;
2229
2230         if (udev->config == NULL) {
2231                 err = usb_get_configuration(udev);
2232                 if (err < 0) {
2233                         dev_err(&udev->dev, "can't read configurations, error %d\n",
2234                                 err);
2235                         return err;
2236                 }
2237         }
2238         if (udev->wusb == 1 && udev->authorized == 0) {
2239                 udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2240                 udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2241                 udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2242         }
2243         else {
2244                 /* read the standard strings and cache them if present */
2245                 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2246                 udev->manufacturer = usb_cache_string(udev,
2247                                                       udev->descriptor.iManufacturer);
2248                 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2249         }
2250         err = usb_enumerate_device_otg(udev);
2251         if (err < 0)
2252                 return err;
2253
2254         usb_detect_interface_quirks(udev);
2255
2256         return 0;
2257 }
2258
2259 static void set_usb_port_removable(struct usb_device *udev)
2260 {
2261         struct usb_device *hdev = udev->parent;
2262         struct usb_hub *hub;
2263         u8 port = udev->portnum;
2264         u16 wHubCharacteristics;
2265         bool removable = true;
2266
2267         if (!hdev)
2268                 return;
2269
2270         hub = hdev_to_hub(udev->parent);
2271
2272         wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2273
2274         if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2275                 return;
2276
2277         if (hub_is_superspeed(hdev)) {
2278                 if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2279                                 & (1 << port))
2280                         removable = false;
2281         } else {
2282                 if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2283                         removable = false;
2284         }
2285
2286         if (removable)
2287                 udev->removable = USB_DEVICE_REMOVABLE;
2288         else
2289                 udev->removable = USB_DEVICE_FIXED;
2290 }
2291
2292 /**
2293  * usb_new_device - perform initial device setup (usbcore-internal)
2294  * @udev: newly addressed device (in ADDRESS state)
2295  *
2296  * This is called with devices which have been detected but not fully
2297  * enumerated.  The device descriptor is available, but not descriptors
2298  * for any device configuration.  The caller must have locked either
2299  * the parent hub (if udev is a normal device) or else the
2300  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
2301  * udev has already been installed, but udev is not yet visible through
2302  * sysfs or other filesystem code.
2303  *
2304  * It will return if the device is configured properly or not.  Zero if
2305  * the interface was registered with the driver core; else a negative
2306  * errno value.
2307  *
2308  * This call is synchronous, and may not be used in an interrupt context.
2309  *
2310  * Only the hub driver or root-hub registrar should ever call this.
2311  */
2312 int usb_new_device(struct usb_device *udev)
2313 {
2314         int err;
2315
2316         if (udev->parent) {
2317                 /* Initialize non-root-hub device wakeup to disabled;
2318                  * device (un)configuration controls wakeup capable
2319                  * sysfs power/wakeup controls wakeup enabled/disabled
2320                  */
2321                 device_init_wakeup(&udev->dev, 0);
2322         }
2323
2324         /* Tell the runtime-PM framework the device is active */
2325         pm_runtime_set_active(&udev->dev);
2326         pm_runtime_get_noresume(&udev->dev);
2327         pm_runtime_use_autosuspend(&udev->dev);
2328         pm_runtime_enable(&udev->dev);
2329
2330         /* By default, forbid autosuspend for all devices.  It will be
2331          * allowed for hubs during binding.
2332          */
2333         usb_disable_autosuspend(udev);
2334
2335         err = usb_enumerate_device(udev);       /* Read descriptors */
2336         if (err < 0)
2337                 goto fail;
2338         dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2339                         udev->devnum, udev->bus->busnum,
2340                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2341         /* export the usbdev device-node for libusb */
2342         udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2343                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2344
2345         /* Tell the world! */
2346         announce_device(udev);
2347
2348         if (udev->serial)
2349                 add_device_randomness(udev->serial, strlen(udev->serial));
2350         if (udev->product)
2351                 add_device_randomness(udev->product, strlen(udev->product));
2352         if (udev->manufacturer)
2353                 add_device_randomness(udev->manufacturer,
2354                                       strlen(udev->manufacturer));
2355
2356         device_enable_async_suspend(&udev->dev);
2357
2358         /*
2359          * check whether the hub marks this port as non-removable. Do it
2360          * now so that platform-specific data can override it in
2361          * device_add()
2362          */
2363         if (udev->parent)
2364                 set_usb_port_removable(udev);
2365
2366         /* Register the device.  The device driver is responsible
2367          * for configuring the device and invoking the add-device
2368          * notifier chain (used by usbfs and possibly others).
2369          */
2370         err = device_add(&udev->dev);
2371         if (err) {
2372                 dev_err(&udev->dev, "can't device_add, error %d\n", err);
2373                 goto fail;
2374         }
2375
2376         (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2377         usb_mark_last_busy(udev);
2378         pm_runtime_put_sync_autosuspend(&udev->dev);
2379         return err;
2380
2381 fail:
2382         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2383         pm_runtime_disable(&udev->dev);
2384         pm_runtime_set_suspended(&udev->dev);
2385         return err;
2386 }
2387
2388
2389 /**
2390  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2391  * @usb_dev: USB device
2392  *
2393  * Move the USB device to a very basic state where interfaces are disabled
2394  * and the device is in fact unconfigured and unusable.
2395  *
2396  * We share a lock (that we have) with device_del(), so we need to
2397  * defer its call.
2398  */
2399 int usb_deauthorize_device(struct usb_device *usb_dev)
2400 {
2401         usb_lock_device(usb_dev);
2402         if (usb_dev->authorized == 0)
2403                 goto out_unauthorized;
2404
2405         usb_dev->authorized = 0;
2406         usb_set_configuration(usb_dev, -1);
2407
2408         kfree(usb_dev->product);
2409         usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2410         kfree(usb_dev->manufacturer);
2411         usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2412         kfree(usb_dev->serial);
2413         usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2414
2415         usb_destroy_configuration(usb_dev);
2416         usb_dev->descriptor.bNumConfigurations = 0;
2417
2418 out_unauthorized:
2419         usb_unlock_device(usb_dev);
2420         return 0;
2421 }
2422
2423
2424 int usb_authorize_device(struct usb_device *usb_dev)
2425 {
2426         int result = 0, c;
2427
2428         usb_lock_device(usb_dev);
2429         if (usb_dev->authorized == 1)
2430                 goto out_authorized;
2431
2432         result = usb_autoresume_device(usb_dev);
2433         if (result < 0) {
2434                 dev_err(&usb_dev->dev,
2435                         "can't autoresume for authorization: %d\n", result);
2436                 goto error_autoresume;
2437         }
2438         result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
2439         if (result < 0) {
2440                 dev_err(&usb_dev->dev, "can't re-read device descriptor for "
2441                         "authorization: %d\n", result);
2442                 goto error_device_descriptor;
2443         }
2444
2445         kfree(usb_dev->product);
2446         usb_dev->product = NULL;
2447         kfree(usb_dev->manufacturer);
2448         usb_dev->manufacturer = NULL;
2449         kfree(usb_dev->serial);
2450         usb_dev->serial = NULL;
2451
2452         usb_dev->authorized = 1;
2453         result = usb_enumerate_device(usb_dev);
2454         if (result < 0)
2455                 goto error_enumerate;
2456         /* Choose and set the configuration.  This registers the interfaces
2457          * with the driver core and lets interface drivers bind to them.
2458          */
2459         c = usb_choose_configuration(usb_dev);
2460         if (c >= 0) {
2461                 result = usb_set_configuration(usb_dev, c);
2462                 if (result) {
2463                         dev_err(&usb_dev->dev,
2464                                 "can't set config #%d, error %d\n", c, result);
2465                         /* This need not be fatal.  The user can try to
2466                          * set other configurations. */
2467                 }
2468         }
2469         dev_info(&usb_dev->dev, "authorized to connect\n");
2470
2471 error_enumerate:
2472 error_device_descriptor:
2473         usb_autosuspend_device(usb_dev);
2474 error_autoresume:
2475 out_authorized:
2476         usb_unlock_device(usb_dev);     // complements locktree
2477         return result;
2478 }
2479
2480
2481 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
2482 static unsigned hub_is_wusb(struct usb_hub *hub)
2483 {
2484         struct usb_hcd *hcd;
2485         if (hub->hdev->parent != NULL)  /* not a root hub? */
2486                 return 0;
2487         hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
2488         return hcd->wireless;
2489 }
2490
2491
2492 #define PORT_RESET_TRIES        5
2493 #define SET_ADDRESS_TRIES       2
2494 #define GET_DESCRIPTOR_TRIES    2
2495 #define SET_CONFIG_TRIES        (2 * (use_both_schemes + 1))
2496 #define USE_NEW_SCHEME(i)       ((i) / 2 == (int)old_scheme_first)
2497
2498 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
2499 #define HUB_SHORT_RESET_TIME    10
2500 #define HUB_BH_RESET_TIME       50
2501 #define HUB_LONG_RESET_TIME     200
2502 #define HUB_RESET_TIMEOUT       800
2503
2504 static int hub_port_reset(struct usb_hub *hub, int port1,
2505                         struct usb_device *udev, unsigned int delay, bool warm);
2506
2507 /* Is a USB 3.0 port in the Inactive or Complinance Mode state?
2508  * Port worm reset is required to recover
2509  */
2510 static bool hub_port_warm_reset_required(struct usb_hub *hub, u16 portstatus)
2511 {
2512         return hub_is_superspeed(hub->hdev) &&
2513                 (((portstatus & USB_PORT_STAT_LINK_STATE) ==
2514                   USB_SS_PORT_LS_SS_INACTIVE) ||
2515                  ((portstatus & USB_PORT_STAT_LINK_STATE) ==
2516                   USB_SS_PORT_LS_COMP_MOD)) ;
2517 }
2518
2519 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2520                         struct usb_device *udev, unsigned int delay, bool warm)
2521 {
2522         int delay_time, ret;
2523         u16 portstatus;
2524         u16 portchange;
2525
2526         for (delay_time = 0;
2527                         delay_time < HUB_RESET_TIMEOUT;
2528                         delay_time += delay) {
2529                 /* wait to give the device a chance to reset */
2530                 msleep(delay);
2531
2532                 /* read and decode port status */
2533                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2534                 if (ret < 0)
2535                         return ret;
2536
2537                 /* The port state is unknown until the reset completes. */
2538                 if ((portstatus & USB_PORT_STAT_RESET))
2539                         goto delay;
2540
2541                 /*
2542                  * Some buggy devices require a warm reset to be issued even
2543                  * when the port appears not to be connected.
2544                  */
2545                 if (!warm) {
2546                         /*
2547                          * Some buggy devices can cause an NEC host controller
2548                          * to transition to the "Error" state after a hot port
2549                          * reset.  This will show up as the port state in
2550                          * "Inactive", and the port may also report a
2551                          * disconnect.  Forcing a warm port reset seems to make
2552                          * the device work.
2553                          *
2554                          * See https://bugzilla.kernel.org/show_bug.cgi?id=41752
2555                          */
2556                         if (hub_port_warm_reset_required(hub, portstatus)) {
2557                                 int ret;
2558
2559                                 if ((portchange & USB_PORT_STAT_C_CONNECTION))
2560                                         clear_port_feature(hub->hdev, port1,
2561                                                         USB_PORT_FEAT_C_CONNECTION);
2562                                 if (portchange & USB_PORT_STAT_C_LINK_STATE)
2563                                         clear_port_feature(hub->hdev, port1,
2564                                                         USB_PORT_FEAT_C_PORT_LINK_STATE);
2565                                 if (portchange & USB_PORT_STAT_C_RESET)
2566                                         clear_port_feature(hub->hdev, port1,
2567                                                         USB_PORT_FEAT_C_RESET);
2568                                 dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
2569                                                 port1);
2570                                 ret = hub_port_reset(hub, port1,
2571                                                 udev, HUB_BH_RESET_TIME,
2572                                                 true);
2573                                 if ((portchange & USB_PORT_STAT_C_CONNECTION))
2574                                         clear_port_feature(hub->hdev, port1,
2575                                                         USB_PORT_FEAT_C_CONNECTION);
2576                                 return ret;
2577                         }
2578                         /* Device went away? */
2579                         if (!(portstatus & USB_PORT_STAT_CONNECTION))
2580                                 return -ENOTCONN;
2581
2582                         /* bomb out completely if the connection bounced */
2583                         if ((portchange & USB_PORT_STAT_C_CONNECTION))
2584                                 return -ENOTCONN;
2585
2586                         if ((portstatus & USB_PORT_STAT_ENABLE)) {
2587                                 if (hub_is_wusb(hub))
2588                                         udev->speed = USB_SPEED_WIRELESS;
2589                                 else if (hub_is_superspeed(hub->hdev))
2590                                         udev->speed = USB_SPEED_SUPER;
2591                                 else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2592                                         udev->speed = USB_SPEED_HIGH;
2593                                 else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2594                                         udev->speed = USB_SPEED_LOW;
2595                                 else
2596                                         udev->speed = USB_SPEED_FULL;
2597                                 return 0;
2598                         }
2599                 } else {
2600                         if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
2601                                         hub_port_warm_reset_required(hub,
2602                                                 portstatus))
2603                                 return -ENOTCONN;
2604
2605                         return 0;
2606                 }
2607
2608 delay:
2609                 /* switch to the long delay after two short delay failures */
2610                 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2611                         delay = HUB_LONG_RESET_TIME;
2612
2613                 dev_dbg (hub->intfdev,
2614                         "port %d not %sreset yet, waiting %dms\n",
2615                         port1, warm ? "warm " : "", delay);
2616         }
2617
2618         return -EBUSY;
2619 }
2620
2621 static void hub_port_finish_reset(struct usb_hub *hub, int port1,
2622                         struct usb_device *udev, int *status, bool warm)
2623 {
2624         switch (*status) {
2625         case 0:
2626                 if (!warm) {
2627                         struct usb_hcd *hcd;
2628                         /* TRSTRCY = 10 ms; plus some extra */
2629                         msleep(10 + 40);
2630                         update_devnum(udev, 0);
2631                         hcd = bus_to_hcd(udev->bus);
2632                         /* The xHC may think the device is already reset,
2633                          * so ignore the status.
2634                          */
2635                         if (hcd->driver->reset_device)
2636                                 hcd->driver->reset_device(hcd, udev);
2637                 }
2638                 /* FALL THROUGH */
2639         case -ENOTCONN:
2640         case -ENODEV:
2641                 clear_port_feature(hub->hdev,
2642                                 port1, USB_PORT_FEAT_C_RESET);
2643                 /* FIXME need disconnect() for NOTATTACHED device */
2644                 if (hub_is_superspeed(hub->hdev)) {
2645                         clear_port_feature(hub->hdev, port1,
2646                                         USB_PORT_FEAT_C_BH_PORT_RESET);
2647                         clear_port_feature(hub->hdev, port1,
2648                                         USB_PORT_FEAT_C_PORT_LINK_STATE);
2649                 }
2650                 if (!warm)
2651                         usb_set_device_state(udev, *status
2652                                         ? USB_STATE_NOTATTACHED
2653                                         : USB_STATE_DEFAULT);
2654                 break;
2655         }
2656 }
2657
2658 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
2659 static int hub_port_reset(struct usb_hub *hub, int port1,
2660                         struct usb_device *udev, unsigned int delay, bool warm)
2661 {
2662         int i, status;
2663
2664         if (!warm) {
2665                 /* Block EHCI CF initialization during the port reset.
2666                  * Some companion controllers don't like it when they mix.
2667                  */
2668                 down_read(&ehci_cf_port_reset_rwsem);
2669         } else {
2670                 if (!hub_is_superspeed(hub->hdev)) {
2671                         dev_err(hub->intfdev, "only USB3 hub support "
2672                                                 "warm reset\n");
2673                         return -EINVAL;
2674                 }
2675         }
2676
2677         /* Reset the port */
2678         for (i = 0; i < PORT_RESET_TRIES; i++) {
2679                 status = set_port_feature(hub->hdev, port1, (warm ?
2680                                         USB_PORT_FEAT_BH_PORT_RESET :
2681                                         USB_PORT_FEAT_RESET));
2682                 if (status) {
2683                         dev_err(hub->intfdev,
2684                                         "cannot %sreset port %d (err = %d)\n",
2685                                         warm ? "warm " : "", port1, status);
2686                 } else {
2687                         status = hub_port_wait_reset(hub, port1, udev, delay,
2688                                                                 warm);
2689                         if (status && status != -ENOTCONN)
2690                                 dev_dbg(hub->intfdev,
2691                                                 "port_wait_reset: err = %d\n",
2692                                                 status);
2693                 }
2694
2695                 /* return on disconnect or reset */
2696                 if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
2697                         hub_port_finish_reset(hub, port1, udev, &status, warm);
2698                         goto done;
2699                 }
2700
2701                 dev_dbg (hub->intfdev,
2702                         "port %d not enabled, trying %sreset again...\n",
2703                         port1, warm ? "warm " : "");
2704                 delay = HUB_LONG_RESET_TIME;
2705         }
2706
2707         dev_err (hub->intfdev,
2708                 "Cannot enable port %i.  Maybe the USB cable is bad?\n",
2709                 port1);
2710
2711 done:
2712         if (!warm)
2713                 up_read(&ehci_cf_port_reset_rwsem);
2714
2715         return status;
2716 }
2717
2718 /* Check if a port is power on */
2719 static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
2720 {
2721         int ret = 0;
2722
2723         if (hub_is_superspeed(hub->hdev)) {
2724                 if (portstatus & USB_SS_PORT_STAT_POWER)
2725                         ret = 1;
2726         } else {
2727                 if (portstatus & USB_PORT_STAT_POWER)
2728                         ret = 1;
2729         }
2730
2731         return ret;
2732 }
2733
2734 #ifdef  CONFIG_PM
2735
2736 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
2737 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
2738 {
2739         int ret = 0;
2740
2741         if (hub_is_superspeed(hub->hdev)) {
2742                 if ((portstatus & USB_PORT_STAT_LINK_STATE)
2743                                 == USB_SS_PORT_LS_U3)
2744                         ret = 1;
2745         } else {
2746                 if (portstatus & USB_PORT_STAT_SUSPEND)
2747                         ret = 1;
2748         }
2749
2750         return ret;
2751 }
2752
2753 /* Determine whether the device on a port is ready for a normal resume,
2754  * is ready for a reset-resume, or should be disconnected.
2755  */
2756 static int check_port_resume_type(struct usb_device *udev,
2757                 struct usb_hub *hub, int port1,
2758                 int status, unsigned portchange, unsigned portstatus)
2759 {
2760         /* Is the device still present? */
2761         if (status || port_is_suspended(hub, portstatus) ||
2762                         !port_is_power_on(hub, portstatus) ||
2763                         !(portstatus & USB_PORT_STAT_CONNECTION)) {
2764                 if (status >= 0)
2765                         status = -ENODEV;
2766         }
2767
2768         /* Can't do a normal resume if the port isn't enabled,
2769          * so try a reset-resume instead.
2770          */
2771         else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2772                 if (udev->persist_enabled)
2773                         udev->reset_resume = 1;
2774                 else
2775                         status = -ENODEV;
2776         }
2777
2778         if (status) {
2779                 dev_dbg(hub->intfdev,
2780                                 "port %d status %04x.%04x after resume, %d\n",
2781                                 port1, portchange, portstatus, status);
2782         } else if (udev->reset_resume) {
2783
2784                 /* Late port handoff can set status-change bits */
2785                 if (portchange & USB_PORT_STAT_C_CONNECTION)
2786                         clear_port_feature(hub->hdev, port1,
2787                                         USB_PORT_FEAT_C_CONNECTION);
2788                 if (portchange & USB_PORT_STAT_C_ENABLE)
2789                         clear_port_feature(hub->hdev, port1,
2790                                         USB_PORT_FEAT_C_ENABLE);
2791         }
2792
2793         return status;
2794 }
2795
2796 int usb_disable_ltm(struct usb_device *udev)
2797 {
2798         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2799
2800         /* Check if the roothub and device supports LTM. */
2801         if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2802                         !usb_device_supports_ltm(udev))
2803                 return 0;
2804
2805         /* Clear Feature LTM Enable can only be sent if the device is
2806          * configured.
2807          */
2808         if (!udev->actconfig)
2809                 return 0;
2810
2811         return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2812                         USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2813                         USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2814                         USB_CTRL_SET_TIMEOUT);
2815 }
2816 EXPORT_SYMBOL_GPL(usb_disable_ltm);
2817
2818 void usb_enable_ltm(struct usb_device *udev)
2819 {
2820         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2821
2822         /* Check if the roothub and device supports LTM. */
2823         if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2824                         !usb_device_supports_ltm(udev))
2825                 return;
2826
2827         /* Set Feature LTM Enable can only be sent if the device is
2828          * configured.
2829          */
2830         if (!udev->actconfig)
2831                 return;
2832
2833         usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2834                         USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2835                         USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2836                         USB_CTRL_SET_TIMEOUT);
2837 }
2838 EXPORT_SYMBOL_GPL(usb_enable_ltm);
2839
2840 #ifdef  CONFIG_USB_SUSPEND
2841 /*
2842  * usb_disable_function_remotewakeup - disable usb3.0
2843  * device's function remote wakeup
2844  * @udev: target device
2845  *
2846  * Assume there's only one function on the USB 3.0
2847  * device and disable remote wake for the first
2848  * interface. FIXME if the interface association
2849  * descriptor shows there's more than one function.
2850  */
2851 static int usb_disable_function_remotewakeup(struct usb_device *udev)
2852 {
2853         return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2854                                 USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
2855                                 USB_INTRF_FUNC_SUSPEND, 0, NULL, 0,
2856                                 USB_CTRL_SET_TIMEOUT);
2857 }
2858
2859 /*
2860  * usb_port_suspend - suspend a usb device's upstream port
2861  * @udev: device that's no longer in active use, not a root hub
2862  * Context: must be able to sleep; device not locked; pm locks held
2863  *
2864  * Suspends a USB device that isn't in active use, conserving power.
2865  * Devices may wake out of a suspend, if anything important happens,
2866  * using the remote wakeup mechanism.  They may also be taken out of
2867  * suspend by the host, using usb_port_resume().  It's also routine
2868  * to disconnect devices while they are suspended.
2869  *
2870  * This only affects the USB hardware for a device; its interfaces
2871  * (and, for hubs, child devices) must already have been suspended.
2872  *
2873  * Selective port suspend reduces power; most suspended devices draw
2874  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
2875  * All devices below the suspended port are also suspended.
2876  *
2877  * Devices leave suspend state when the host wakes them up.  Some devices
2878  * also support "remote wakeup", where the device can activate the USB
2879  * tree above them to deliver data, such as a keypress or packet.  In
2880  * some cases, this wakes the USB host.
2881  *
2882  * Suspending OTG devices may trigger HNP, if that's been enabled
2883  * between a pair of dual-role devices.  That will change roles, such
2884  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
2885  *
2886  * Devices on USB hub ports have only one "suspend" state, corresponding
2887  * to ACPI D2, "may cause the device to lose some context".
2888  * State transitions include:
2889  *
2890  *   - suspend, resume ... when the VBUS power link stays live
2891  *   - suspend, disconnect ... VBUS lost
2892  *
2893  * Once VBUS drop breaks the circuit, the port it's using has to go through
2894  * normal re-enumeration procedures, starting with enabling VBUS power.
2895  * Other than re-initializing the hub (plug/unplug, except for root hubs),
2896  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
2897  * timer, no SRP, no requests through sysfs.
2898  *
2899  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
2900  * the root hub for their bus goes into global suspend ... so we don't
2901  * (falsely) update the device power state to say it suspended.
2902  *
2903  * Returns 0 on success, else negative errno.
2904  */
2905 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2906 {
2907         struct usb_hub  *hub = hdev_to_hub(udev->parent);
2908         int             port1 = udev->portnum;
2909         int             status;
2910
2911         /* enable remote wakeup when appropriate; this lets the device
2912          * wake up the upstream hub (including maybe the root hub).
2913          *
2914          * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
2915          * we don't explicitly enable it here.
2916          */
2917         if (udev->do_remote_wakeup) {
2918                 if (!hub_is_superspeed(hub->hdev)) {
2919                         status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2920                                         USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2921                                         USB_DEVICE_REMOTE_WAKEUP, 0,
2922                                         NULL, 0,
2923                                         USB_CTRL_SET_TIMEOUT);
2924                 } else {
2925                         /* Assume there's only one function on the USB 3.0
2926                          * device and enable remote wake for the first
2927                          * interface. FIXME if the interface association
2928                          * descriptor shows there's more than one function.
2929                          */
2930                         status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2931                                         USB_REQ_SET_FEATURE,
2932                                         USB_RECIP_INTERFACE,
2933                                         USB_INTRF_FUNC_SUSPEND,
2934                                         USB_INTRF_FUNC_SUSPEND_RW |
2935                                         USB_INTRF_FUNC_SUSPEND_LP,
2936                                         NULL, 0,
2937                                         USB_CTRL_SET_TIMEOUT);
2938                 }
2939                 if (status) {
2940                         dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
2941                                         status);
2942                         /* bail if autosuspend is requested */
2943                         if (PMSG_IS_AUTO(msg))
2944                                 return status;
2945                 }
2946         }
2947
2948         /* disable USB2 hardware LPM */
2949         if (udev->usb2_hw_lpm_enabled == 1)
2950                 usb_set_usb2_hardware_lpm(udev, 0);
2951
2952         if (usb_disable_ltm(udev)) {
2953                 dev_err(&udev->dev, "%s Failed to disable LTM before suspend\n.",
2954                                 __func__);
2955                 return -ENOMEM;
2956         }
2957         if (usb_unlocked_disable_lpm(udev)) {
2958                 dev_err(&udev->dev, "%s Failed to disable LPM before suspend\n.",
2959                                 __func__);
2960                 return -ENOMEM;
2961         }
2962
2963         /* see 7.1.7.6 */
2964         if (hub_is_superspeed(hub->hdev))
2965                 status = set_port_feature(hub->hdev,
2966                                 port1 | (USB_SS_PORT_LS_U3 << 3),
2967                                 USB_PORT_FEAT_LINK_STATE);
2968         else
2969                 status = set_port_feature(hub->hdev, port1,
2970                                                 USB_PORT_FEAT_SUSPEND);
2971         if (status) {
2972                 dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
2973                                 port1, status);
2974                 /* paranoia:  "should not happen" */
2975                 if (udev->do_remote_wakeup) {
2976                         if (!hub_is_superspeed(hub->hdev)) {
2977                                 (void) usb_control_msg(udev,
2978                                                 usb_sndctrlpipe(udev, 0),
2979                                                 USB_REQ_CLEAR_FEATURE,
2980                                                 USB_RECIP_DEVICE,
2981                                                 USB_DEVICE_REMOTE_WAKEUP, 0,
2982                                                 NULL, 0,
2983                                                 USB_CTRL_SET_TIMEOUT);
2984                         } else
2985                                 (void) usb_disable_function_remotewakeup(udev);
2986
2987                 }
2988
2989                 /* Try to enable USB2 hardware LPM again */
2990                 if (udev->usb2_hw_lpm_capable == 1)
2991                         usb_set_usb2_hardware_lpm(udev, 1);
2992
2993                 /* Try to enable USB3 LTM and LPM again */
2994                 usb_enable_ltm(udev);
2995                 usb_unlocked_enable_lpm(udev);
2996
2997                 /* System sleep transitions should never fail */
2998                 if (!PMSG_IS_AUTO(msg))
2999                         status = 0;
3000         } else {
3001                 /* device has up to 10 msec to fully suspend */
3002                 dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3003                                 (PMSG_IS_AUTO(msg) ? "auto-" : ""),
3004                                 udev->do_remote_wakeup);
3005                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
3006                 udev->port_is_suspended = 1;
3007                 msleep(10);
3008         }
3009         usb_mark_last_busy(hub->hdev);
3010         return status;
3011 }
3012
3013 /*
3014  * If the USB "suspend" state is in use (rather than "global suspend"),
3015  * many devices will be individually taken out of suspend state using
3016  * special "resume" signaling.  This routine kicks in shortly after
3017  * hardware resume signaling is finished, either because of selective
3018  * resume (by host) or remote wakeup (by device) ... now see what changed
3019  * in the tree that's rooted at this device.
3020  *
3021  * If @udev->reset_resume is set then the device is reset before the
3022  * status check is done.
3023  */
3024 static int finish_port_resume(struct usb_device *udev)
3025 {
3026         int     status = 0;
3027         u16     devstatus = 0;
3028
3029         /* caller owns the udev device lock */
3030         dev_dbg(&udev->dev, "%s\n",
3031                 udev->reset_resume ? "finish reset-resume" : "finish resume");
3032
3033         /* usb ch9 identifies four variants of SUSPENDED, based on what
3034          * state the device resumes to.  Linux currently won't see the
3035          * first two on the host side; they'd be inside hub_port_init()
3036          * during many timeouts, but khubd can't suspend until later.
3037          */
3038         usb_set_device_state(udev, udev->actconfig
3039                         ? USB_STATE_CONFIGURED
3040                         : USB_STATE_ADDRESS);
3041
3042         /* 10.5.4.5 says not to reset a suspended port if the attached
3043          * device is enabled for remote wakeup.  Hence the reset
3044          * operation is carried out here, after the port has been
3045          * resumed.
3046          */
3047         if (udev->reset_resume)
3048  retry_reset_resume:
3049                 status = usb_reset_and_verify_device(udev);
3050
3051         /* 10.5.4.5 says be sure devices in the tree are still there.
3052          * For now let's assume the device didn't go crazy on resume,
3053          * and device drivers will know about any resume quirks.
3054          */
3055         if (status == 0) {
3056                 devstatus = 0;
3057                 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3058                 if (status >= 0)
3059                         status = (status > 0 ? 0 : -ENODEV);
3060
3061                 /* If a normal resume failed, try doing a reset-resume */
3062                 if (status && !udev->reset_resume && udev->persist_enabled) {
3063                         dev_dbg(&udev->dev, "retry with reset-resume\n");
3064                         udev->reset_resume = 1;
3065                         goto retry_reset_resume;
3066                 }
3067         }
3068
3069         if (status) {
3070                 dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3071                                 status);
3072         /*
3073          * There are a few quirky devices which violate the standard
3074          * by claiming to have remote wakeup enabled after a reset,
3075          * which crash if the feature is cleared, hence check for
3076          * udev->reset_resume
3077          */
3078         } else if (udev->actconfig && !udev->reset_resume) {
3079                 if (!hub_is_superspeed(udev->parent)) {
3080                         le16_to_cpus(&devstatus);
3081                         if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3082                                 status = usb_control_msg(udev,
3083                                                 usb_sndctrlpipe(udev, 0),
3084                                                 USB_REQ_CLEAR_FEATURE,
3085                                                 USB_RECIP_DEVICE,
3086                                                 USB_DEVICE_REMOTE_WAKEUP, 0,
3087                                                 NULL, 0,
3088                                                 USB_CTRL_SET_TIMEOUT);
3089                 } else {
3090                         status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3091                                         &devstatus);
3092                         le16_to_cpus(&devstatus);
3093                         if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3094                                         | USB_INTRF_STAT_FUNC_RW))
3095                                 status =
3096                                         usb_disable_function_remotewakeup(udev);
3097                 }
3098
3099                 if (status)
3100                         dev_dbg(&udev->dev,
3101                                 "disable remote wakeup, status %d\n",
3102                                 status);
3103                 status = 0;
3104         }
3105         return status;
3106 }
3107
3108 /*
3109  * usb_port_resume - re-activate a suspended usb device's upstream port
3110  * @udev: device to re-activate, not a root hub
3111  * Context: must be able to sleep; device not locked; pm locks held
3112  *
3113  * This will re-activate the suspended device, increasing power usage
3114  * while letting drivers communicate again with its endpoints.
3115  * USB resume explicitly guarantees that the power session between
3116  * the host and the device is the same as it was when the device
3117  * suspended.
3118  *
3119  * If @udev->reset_resume is set then this routine won't check that the
3120  * port is still enabled.  Furthermore, finish_port_resume() above will
3121  * reset @udev.  The end result is that a broken power session can be
3122  * recovered and @udev will appear to persist across a loss of VBUS power.
3123  *
3124  * For example, if a host controller doesn't maintain VBUS suspend current
3125  * during a system sleep or is reset when the system wakes up, all the USB
3126  * power sessions below it will be broken.  This is especially troublesome
3127  * for mass-storage devices containing mounted filesystems, since the
3128  * device will appear to have disconnected and all the memory mappings
3129  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3130  * made to appear as if it had not disconnected.
3131  *
3132  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3133  * every effort to insure that the same device is present after the
3134  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3135  * quite possible for a device to remain unaltered but its media to be
3136  * changed.  If the user replaces a flash memory card while the system is
3137  * asleep, he will have only himself to blame when the filesystem on the
3138  * new card is corrupted and the system crashes.
3139  *
3140  * Returns 0 on success, else negative errno.
3141  */
3142 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3143 {
3144         struct usb_hub  *hub = hdev_to_hub(udev->parent);
3145         int             port1 = udev->portnum;
3146         int             status;
3147         u16             portchange, portstatus;
3148
3149         /* Skip the initial Clear-Suspend step for a remote wakeup */
3150         status = hub_port_status(hub, port1, &portstatus, &portchange);
3151         if (status == 0 && !port_is_suspended(hub, portstatus))
3152                 goto SuspendCleared;
3153
3154         // dev_dbg(hub->intfdev, "resume port %d\n", port1);
3155
3156         set_bit(port1, hub->busy_bits);
3157
3158         /* see 7.1.7.7; affects power usage, but not budgeting */
3159         if (hub_is_superspeed(hub->hdev))
3160                 status = set_port_feature(hub->hdev,
3161                                 port1 | (USB_SS_PORT_LS_U0 << 3),
3162                                 USB_PORT_FEAT_LINK_STATE);
3163         else
3164                 status = clear_port_feature(hub->hdev,
3165                                 port1, USB_PORT_FEAT_SUSPEND);
3166         if (status) {
3167                 dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
3168                                 port1, status);
3169         } else {
3170                 /* drive resume for at least 20 msec */
3171                 dev_dbg(&udev->dev, "usb %sresume\n",
3172                                 (PMSG_IS_AUTO(msg) ? "auto-" : ""));
3173                 msleep(25);
3174
3175                 /* Virtual root hubs can trigger on GET_PORT_STATUS to
3176                  * stop resume signaling.  Then finish the resume
3177                  * sequence.
3178                  */
3179                 status = hub_port_status(hub, port1, &portstatus, &portchange);
3180
3181                 /* TRSMRCY = 10 msec */
3182                 msleep(10);
3183         }
3184
3185  SuspendCleared:
3186         if (status == 0) {
3187                 udev->port_is_suspended = 0;
3188                 if (hub_is_superspeed(hub->hdev)) {
3189                         if (portchange & USB_PORT_STAT_C_LINK_STATE)
3190                                 clear_port_feature(hub->hdev, port1,
3191                                         USB_PORT_FEAT_C_PORT_LINK_STATE);
3192                 } else {
3193                         if (portchange & USB_PORT_STAT_C_SUSPEND)
3194                                 clear_port_feature(hub->hdev, port1,
3195                                                 USB_PORT_FEAT_C_SUSPEND);
3196                 }
3197         }