[PATCH net] net/mlx5: Lag, Return error when enabling MPESW without LAG support

[Tariq Toukan <tariqt@nvidia.com>]

From: Uri Dar <udar@nvidia.com>

When firmware reports a function as not LAG capable (lag_master=0 or
num_lag_ports < 2), mlx5_lag_add_mdev() creates no LAG object for it.
Enabling multiport E-Switch on such a device returns 0 from
mlx5_lag_mpesw_queue_work(), so
"devlink dev param set ... esw_multiport value true" reports success
although nothing was enabled, and a following "devlink dev param show"
still reports false.

Return -EOPNOTSUPP instead. mlx5_lag_mpesw_disable() ignores the return
value, so disabling keeps its current behavior.

Fixes: a32327a3a02c ("net/mlx5: Lag, Control MultiPort E-Switch single FDB mode")
Signed-off-by: Uri Dar <udar@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c
index abf72026c751..549d31812c2f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c
@@ -227,7 +227,7 @@ static int mlx5_lag_mpesw_queue_work(struct mlx5_core_dev *dev,
 	int err = 0;
 
 	if (!ldev)
-		return 0;
+		return -EOPNOTSUPP;
 
 	work = kzalloc_obj(*work);
 	if (!work)

base-commit: b71c101bbb9814d163c00234d43c41f0a17907d4
-- 
2.44.0