net/mlx4: fix CRC stripping capability report

There are two capabilities related to CRC stripping:
1. mlx4 HW capability to perform CRC stripping on a received packet.
This capability is built in mlx4 HW. It should be returned by the API
call mlx4_get_rx_queue_offloads().
2. mlx4 driver capability to enable/disable HW CRC stripping. This
capability is dependent on the driver version.

Before this commit the second capability was falsely returned by
the mentioned API. This commit fixes it by returning the first
capability.
mlx4 HW performs CRC stripping by default and this capability is
always reported as "true".

The ability to enable/disable CRC stripping is supported since this
commit and requires OFED version 4.3-1.5.0.0 or rdma-core version v18.
CRC stripping will be done by default regardless of its configuration
when working with OFED or rdma-core versions earlier than those
previously specified or before this commit.

Fixes: de1df14e6e6ec ("net/mlx4: support CRC strip toggling")
Cc: stable@dpdk.org
Signed-off-by: Ophir Munk <ophirmu@mellanox.com>

diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst
index 9564f89..509ac22 100644 (file)
--- a/doc/guides/nics/mlx4.rst
+++ b/doc/guides/nics/mlx4.rst
@@ -143,6 +143,13 @@ below.
     following limitation: VLAN filtering is not supported with this mode.
     This is the recommended mode in case VLAN filter is not needed.
 
+Limitations
+-----------
+
+- CRC stripping is supported by default and always reported as "true".
+  The ability to enable/disable CRC stripping requires OFED version
+  4.3-1.5.0.0 and above  or rdma-core version v18 and above.
+
 Prerequisites
 -------------
 

diff --git a/drivers/net/mlx4/mlx4_rxq.c b/drivers/net/mlx4/mlx4_rxq.c
index 65f0994..0650b10 100644 (file)
--- a/drivers/net/mlx4/mlx4_rxq.c
+++ b/drivers/net/mlx4/mlx4_rxq.c
@@ -665,10 +665,9 @@ mlx4_rxq_detach(struct rxq *rxq)
 uint64_t
 mlx4_get_rx_queue_offloads(struct priv *priv)
 {
-       uint64_t offloads = DEV_RX_OFFLOAD_SCATTER;
+       uint64_t offloads = DEV_RX_OFFLOAD_SCATTER |
+                           DEV_RX_OFFLOAD_CRC_STRIP;
 
-       if (priv->hw_fcs_strip)
-               offloads |= DEV_RX_OFFLOAD_CRC_STRIP;
        if (priv->hw_csum)
                offloads |= DEV_RX_OFFLOAD_CHECKSUM;
        return offloads;