net/mlx4_en: Pad ethernet packets smaller than 17 bytes

Hardware can't accept packets smaller than 17 bytes. Therefore need to
pad with zeros.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 8dc7637..781ebca 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -585,7 +585,13 @@
 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
 
 	if (skb->len <= spc) {
-		inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
+		if (likely(skb->len >= MIN_PKT_LEN)) {
+			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
+		} else {
+			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
+			memset(((void *)(inl + 1)) + skb->len, 0,
+			       MIN_PKT_LEN - skb->len);
+		}
 		skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb));
 		if (skb_shinfo(skb)->nr_frags)
 			memcpy(((void *)(inl + 1)) + skb_headlen(skb), fragptr,