IB/mlx5: Fix RSS Toeplitz setup to be aligned with the HW specification

The specification for the Toeplitz function doesn't require to set the key
explicitly to be symmetric. In case a symmetric functionality is required
a symmetric key can be simply used.

Wrongly forcing the algorithm to symmetric causes the wrong packet
distribution and a performance degradation.

Link: https://lore.kernel.org/r/20190723065733.4899-7-leon@kernel.org
Cc: <stable@vger.kernel.org> # 4.7
Fixes: 28d6137008b2 ("IB/mlx5: Add RSS QP support")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Alex Vainman <alexv@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 615cc67715167de6d63fd78dc4a219280f8af84b..379328b2598fd59f1de6674df0918f4d6d79a91c 100644 (file)
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -1713,7 +1713,6 @@ static int create_rss_raw_qp_tir(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
                }
 
                MLX5_SET(tirc, tirc, rx_hash_fn, MLX5_RX_HASH_FN_TOEPLITZ);
-               MLX5_SET(tirc, tirc, rx_hash_symmetric, 1);
                memcpy(rss_key, ucmd.rx_hash_key, len);
                break;
        }