]> git.openfabrics.org - ~shefty/rdma-dev.git/blobdiff - arch/x86/kernel/apb_timer.c
Merge branch 'devicetree/for-x86' of git://git.secretlab.ca/git/linux-2.6 into x86...
[~shefty/rdma-dev.git] / arch / x86 / kernel / apb_timer.c
index 51ef31a89be92848ab65e7b148e6c6bdb0f192ea..671d5aad7a0c9999f662d7c404e55b1aac99d017 100644 (file)
@@ -508,64 +508,12 @@ static int apbt_next_event(unsigned long delta,
        return 0;
 }
 
-/*
- * APB timer clock is not in sync with pclk on Langwell, which translates to
- * unreliable read value caused by sampling error. the error does not add up
- * overtime and only happens when sampling a 0 as a 1 by mistake. so the time
- * would go backwards. the following code is trying to prevent time traveling
- * backwards. little bit paranoid.
- */
 static cycle_t apbt_read_clocksource(struct clocksource *cs)
 {
-       unsigned long t0, t1, t2;
-       static unsigned long last_read;
-
-bad_count:
-       t1 = apbt_readl(phy_cs_timer_id,
-                       APBTMR_N_CURRENT_VALUE);
-       t2 = apbt_readl(phy_cs_timer_id,
-                       APBTMR_N_CURRENT_VALUE);
-       if (unlikely(t1 < t2)) {
-               pr_debug("APBT: read current count error %lx:%lx:%lx\n",
-                        t1, t2, t2 - t1);
-               goto bad_count;
-       }
-       /*
-        * check against cached last read, makes sure time does not go back.
-        * it could be a normal rollover but we will do tripple check anyway
-        */
-       if (unlikely(t2 > last_read)) {
-               /* check if we have a normal rollover */
-               unsigned long raw_intr_status =
-                       apbt_readl_reg(APBTMRS_RAW_INT_STATUS);
-               /*
-                * cs timer interrupt is masked but raw intr bit is set if
-                * rollover occurs. then we read EOI reg to clear it.
-                */
-               if (raw_intr_status & (1 << phy_cs_timer_id)) {
-                       apbt_readl(phy_cs_timer_id, APBTMR_N_EOI);
-                       goto out;
-               }
-               pr_debug("APB CS going back %lx:%lx:%lx ",
-                        t2, last_read, t2 - last_read);
-bad_count_x3:
-               pr_debug("triple check enforced\n");
-               t0 = apbt_readl(phy_cs_timer_id,
-                               APBTMR_N_CURRENT_VALUE);
-               udelay(1);
-               t1 = apbt_readl(phy_cs_timer_id,
-                               APBTMR_N_CURRENT_VALUE);
-               udelay(1);
-               t2 = apbt_readl(phy_cs_timer_id,
-                               APBTMR_N_CURRENT_VALUE);
-               if ((t2 > t1) || (t1 > t0)) {
-                       printk(KERN_ERR "Error: APB CS tripple check failed\n");
-                       goto bad_count_x3;
-               }
-       }
-out:
-       last_read = t2;
-       return (cycle_t)~t2;
+       unsigned long current_count;
+
+       current_count = apbt_readl(phy_cs_timer_id, APBTMR_N_CURRENT_VALUE);
+       return (cycle_t)~current_count;
 }
 
 static int apbt_clocksource_register(void)