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/[email protected]
Cc: <[email protected]> # 4.7
Fixes: 28d6137 ("IB/mlx5: Add RSS QP support")
Signed-off-by: Yishai Hadas <[email protected]>
Reviewed-by: Alex Vainman <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: yishaih

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;
 	}