e1000: Small packets may get corrupted during padding by HW
Tushar Dave [Sat, 15 Sep 2012 10:16:57 +0000 (10:16 +0000)]
On PCI/PCI-X HW, if packet size is less than ETH_ZLEN,
packets may get corrupted during padding by HW.
To WA this issue, pad all small packets manually.

Signed-off-by: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/e1000/e1000_main.c

index 3bfbb8d..bde337e 100644 (file)
@@ -3149,6 +3149,17 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
                return NETDEV_TX_OK;
        }
 
+       /* On PCI/PCI-X HW, if packet size is less than ETH_ZLEN,
+        * packets may get corrupted during padding by HW.
+        * To WA this issue, pad all small packets manually.
+        */
+       if (skb->len < ETH_ZLEN) {
+               if (skb_pad(skb, ETH_ZLEN - skb->len))
+                       return NETDEV_TX_OK;
+               skb->len = ETH_ZLEN;
+               skb_set_tail_pointer(skb, ETH_ZLEN);
+       }
+
        mss = skb_shinfo(skb)->gso_size;
        /* The controller does a simple calculation to
         * make sure there is enough room in the FIFO before