e1000: Small packets may get corrupted during padding by HW

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>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 3bfbb8df8989..bde337ee1a34 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -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