igb: Correcting and improving small packet check and padding

Current implementation mess up the tail pointer. This patch sets skb->tail
correctly.
Also, the small packet check and padding is optimized by using unlikely and
calling skb_pad directly.

Signed-off-by: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index e1ceb37ef12e406fd7ff6dff13b08c18548fcea6..c611cffa788ff4d8c1018a9b705b6affa97443db 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4467,10 +4467,11 @@ static netdev_tx_t igb_xmit_frame(struct sk_buff *skb,
         * The minimum packet size with TCTL.PSP set is 17 so pad the skb
         * in order to meet this minimum size requirement.
         */
-       if (skb->len < 17) {
-               if (skb_padto(skb, 17))
+       if (unlikely(skb->len < 17)) {
+               if (skb_pad(skb, 17 - skb->len))
                        return NETDEV_TX_OK;
                skb->len = 17;
+               skb_set_tail_pointer(skb, 17);
        }
 
        return igb_xmit_frame_ring(skb, igb_tx_queue_mapping(adapter, skb));