mlx4_en: Remove FCS bytes from packet length.

When HW doesn't remove FCS bytes they are reported in the completion
byte count, we don't need to take them to skb.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index b89c36dbf5b3..c2df6c358603 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -581,6 +581,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
                  * Packet is OK - process it.
                  */
                 length = be32_to_cpu(cqe->byte_cnt);
+                length -= ring->fcs_del;
                 ring->bytes += length;
                 ring->packets++;
 
@@ -813,8 +814,11 @@ static int mlx4_en_config_rss_qp(struct mlx4_en_priv *priv, int qpn,
         context->db_rec_addr = cpu_to_be64(ring->wqres.db.dma);
 
         /* Cancel FCS removal if FW allows */
-        if (mdev->dev->caps.flags & MLX4_DEV_CAP_FLAG_FCS_KEEP)
+        if (mdev->dev->caps.flags & MLX4_DEV_CAP_FLAG_FCS_KEEP) {
                 context->param3 |= cpu_to_be32(1 << 29);
+                ring->fcs_del = ETH_FCS_LEN;
+        } else
+                ring->fcs_del = 0;
 
         err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, context, qp, state);
         if (err) {
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 8fda331c65df..207b5add3ca8 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -272,6 +272,7 @@ struct mlx4_en_rx_ring {
         u32 prod;
         u32 cons;
         u32 buf_size;
+        u8  fcs_del;
         void *buf;
         void *rx_info;
         unsigned long bytes;