net/mlx4_en: CHECKSUM_COMPLETE support for fragments

Refine the RX check summing handling to propagate the
hardware provided checksum so that we do not have to
compute it later in software.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -821,14 +821,12 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		skb_record_rx_queue(skb, cq_ring);
 
 		if (likely(dev->features & NETIF_F_RXCSUM)) {
-			if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP |
-						      MLX4_CQE_STATUS_UDP)) {
+			if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP |
+						       MLX4_CQE_STATUS_UDP)) &&
+			    (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
+			    cqe->checksum == cpu_to_be16(0xffff)) {
 				bool l2_tunnel;
 
-				if (!((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
-				      cqe->checksum == cpu_to_be16(0xffff)))
-					goto csum_none;
-
 				l2_tunnel = (dev->hw_enc_features & NETIF_F_RXCSUM) &&
 					(cqe->vlan_my_qpn & cpu_to_be32(MLX4_CQE_L2_TUNNEL));
 				ip_summed = CHECKSUM_UNNECESSARY;