pch_gbe: Fix the issue that the receiving data is not normal.
[~shefty/rdma-dev.git] / drivers / net / pch_gbe / pch_gbe_main.c
index 4c9a7d4f3fcabc0e63047e73ceaaaa18bc15b128..f52d852569fbb5bdd10dac1d014d56247f89d913 100644 (file)
@@ -29,6 +29,7 @@ const char pch_driver_version[] = DRV_VERSION;
 #define PCH_GBE_SHORT_PKT              64
 #define DSC_INIT16                     0xC000
 #define PCH_GBE_DMA_ALIGN              0
+#define PCH_GBE_DMA_PADDING            2
 #define PCH_GBE_WATCHDOG_PERIOD                (1 * HZ)        /* watchdog time */
 #define PCH_GBE_COPYBREAK_DEFAULT      256
 #define PCH_GBE_PCI_BAR                        1
@@ -1365,16 +1366,13 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
        struct pch_gbe_buffer *buffer_info;
        struct pch_gbe_rx_desc *rx_desc;
        u32 length;
-       unsigned char tmp_packet[ETH_HLEN];
        unsigned int i;
        unsigned int cleaned_count = 0;
        bool cleaned = false;
-       struct sk_buff *skb;
+       struct sk_buff *skb, *new_skb;
        u8 dma_status;
        u16 gbec_status;
        u32 tcp_ip_status;
-       u8 skb_copy_flag = 0;
-       u8 skb_padding_flag = 0;
 
        i = rx_ring->next_to_clean;
 
@@ -1418,55 +1416,70 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
                        pr_err("Receive CRC Error\n");
                } else {
                        /* get receive length */
-                       /* length convert[-3], padding[-2] */
-                       length = (rx_desc->rx_words_eob) - 3 - 2;
+                       /* length convert[-3] */
+                       length = (rx_desc->rx_words_eob) - 3;
 
                        /* Decide the data conversion method */
                        if (!adapter->rx_csum) {
                                /* [Header:14][payload] */
-                               skb_padding_flag = 0;
-                               skb_copy_flag = 1;
+                               if (NET_IP_ALIGN) {
+                                       /* Because alignment differs,
+                                        * the new_skb is newly allocated,
+                                        * and data is copied to new_skb.*/
+                                       new_skb = netdev_alloc_skb(netdev,
+                                                        length + NET_IP_ALIGN);
+                                       if (!new_skb) {
+                                               /* dorrop error */
+                                               pr_err("New skb allocation "
+                                                       "Error\n");
+                                               goto dorrop;
+                                       }
+                                       skb_reserve(new_skb, NET_IP_ALIGN);
+                                       memcpy(new_skb->data, skb->data,
+                                              length);
+                                       skb = new_skb;
+                               } else {
+                                       /* DMA buffer is used as SKB as it is.*/
+                                       buffer_info->skb = NULL;
+                               }
                        } else {
                                /* [Header:14][padding:2][payload] */
-                               skb_padding_flag = 1;
-                               if (length < copybreak)
-                                       skb_copy_flag = 1;
-                               else
-                                       skb_copy_flag = 0;
-                       }
-
-                       /* Data conversion */
-                       if (skb_copy_flag) {    /* recycle  skb */
-                               struct sk_buff *new_skb;
-                               new_skb =
-                                   netdev_alloc_skb(netdev,
-                                                    length + NET_IP_ALIGN);
-                               if (new_skb) {
-                                       if (!skb_padding_flag) {
-                                               skb_reserve(new_skb,
-                                                               NET_IP_ALIGN);
+                               /* The length includes padding length */
+                               length = length - PCH_GBE_DMA_PADDING;
+                               if ((length < copybreak) ||
+                                   (NET_IP_ALIGN != PCH_GBE_DMA_PADDING)) {
+                                       /* Because alignment differs,
+                                        * the new_skb is newly allocated,
+                                        * and data is copied to new_skb.
+                                        * Padding data is deleted
+                                        * at the time of a copy.*/
+                                       new_skb = netdev_alloc_skb(netdev,
+                                                        length + NET_IP_ALIGN);
+                                       if (!new_skb) {
+                                               /* dorrop error */
+                                               pr_err("New skb allocation "
+                                                       "Error\n");
+                                               goto dorrop;
                                        }
+                                       skb_reserve(new_skb, NET_IP_ALIGN);
                                        memcpy(new_skb->data, skb->data,
-                                               length);
-                                       /* save the skb
-                                        * in buffer_info as good */
+                                              ETH_HLEN);
+                                       memcpy(&new_skb->data[ETH_HLEN],
+                                              &skb->data[ETH_HLEN +
+                                              PCH_GBE_DMA_PADDING],
+                                              length - ETH_HLEN);
                                        skb = new_skb;
-                               } else if (!skb_padding_flag) {
-                                       /* dorrop error */
-                                       pr_err("New skb allocation Error\n");
-                                       goto dorrop;
+                               } else {
+                                       /* Padding data is deleted
+                                        * by moving header data.*/
+                                       memmove(&skb->data[PCH_GBE_DMA_PADDING],
+                                               &skb->data[0], ETH_HLEN);
+                                       skb_reserve(skb, NET_IP_ALIGN);
+                                       buffer_info->skb = NULL;
                                }
-                       } else {
-                               buffer_info->skb = NULL;
                        }
-                       if (skb_padding_flag) {
-                               memcpy(&tmp_packet[0], &skb->data[0], ETH_HLEN);
-                               memcpy(&skb->data[NET_IP_ALIGN], &tmp_packet[0],
-                                       ETH_HLEN);
-                               skb_reserve(skb, NET_IP_ALIGN);
-
-                       }
-
+                       /* The length includes FCS length */
+                       length = length - ETH_FCS_LEN;
                        /* update status of driver */
                        adapter->stats.rx_bytes += length;
                        adapter->stats.rx_packets++;