net/mlx5: Warn when write combining is not supported

Warn if write combining is not supported, as it can impact latency.
Add the warning message to be printed only when the driver actually
run the test and detect unsupported state, rather than when
inheriting parent's result for SFs.

Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/1752009387-13300-5-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/wc.c b/drivers/net/ethernet/mellanox/mlx5/core/wc.c
index 740b719e7072df683d4476640e5814a196a56a0d..2f0316616fa40b3a13fdf9d3d5817d99df454c79 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/wc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wc.c
@@ -378,6 +378,9 @@ err_create_cq:
        mlx5_free_bfreg(mdev, &sq->bfreg);
 err_alloc_bfreg:
        kfree(sq);
+
+       if (mdev->wc_state == MLX5_WC_STATE_UNSUPPORTED)
+               mlx5_core_warn(mdev, "Write combining is not supported\n");
 }
 
 bool mlx5_wc_support_get(struct mlx5_core_dev *mdev)