Commit a532a7049ba2 for kernel

commit a532a7049ba23edeb2e16f7bb5929314f2e47ca0
Author: Uri Dar <udar@nvidia.com>
Date:   Tue Nov 10 13:43:50 2026 +0200

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

    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>
    Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
    Link: https://patch.msgid.link/20261110114350.2639891-1-tariqt@nvidia.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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)