mlxsw: Strip FCS from incoming packets

FCS of incoming packets is already checked by HW. Just strip it out.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/pci.c

@@ -667,6 +667,7 @@ static void mlxsw_pci_cqe_rdq_handle(struct mlxsw_pci *mlxsw_pci,
 	char *wqe;
 	struct sk_buff *skb;
 	struct mlxsw_rx_info rx_info;
+	u16 byte_count;
 	int err;
 
 	elem_info = mlxsw_pci_queue_elem_info_consumer_get(q);
@@ -686,7 +687,10 @@ static void mlxsw_pci_cqe_rdq_handle(struct mlxsw_pci *mlxsw_pci,
 	rx_info.sys_port = mlxsw_pci_cqe_system_port_get(cqe);
 	rx_info.trap_id = mlxsw_pci_cqe_trap_id_get(cqe);
 
-	skb_put(skb, mlxsw_pci_cqe_byte_count_get(cqe));
+	byte_count = mlxsw_pci_cqe_byte_count_get(cqe);
+	if (mlxsw_pci_cqe_crc_get(cqe))
+		byte_count -= ETH_FCS_LEN;
+	skb_put(skb, byte_count);
 	mlxsw_core_skb_receive(mlxsw_pci->core, skb, &rx_info);
 
 put_new_skb:

drivers/net/ethernet/mellanox/mlxsw/pci.h

@@ -155,6 +155,12 @@ MLXSW_ITEM32(pci, cqe, byte_count, 0x04, 0, 14);
  */
 MLXSW_ITEM32(pci, cqe, trap_id, 0x08, 0, 8);
 
+/* pci_cqe_crc
+ * Length include CRC. Indicates the length field includes
+ * the packet's CRC.
+ */
+MLXSW_ITEM32(pci, cqe, crc, 0x0C, 8, 1);
+
 /* pci_cqe_e
  * CQE with Error.
  */