net/mlx5: E-switch, Destroy legacy fdb table when needed

The cited commit removes eswitch mode none. But when disabling
sriov in legacy mode or changing from switchdev to legacy mode
without sriov enabled, the legacy fdb table is not destroyed.

It is not the right behavior. Destroy legacy fdb table in above
two caes.

Fixes: f019679e ("net/mlx5: E-switch, Remove dependency between sriov and eswitch mode")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/eswitch.c

@@ -1362,6 +1362,9 @@ void mlx5_eswitch_disable_sriov(struct mlx5_eswitch *esw, bool clear_vf)
 
 		devl_rate_nodes_destroy(devlink);
 	}
+	/* Destroy legacy fdb when disabling sriov in legacy mode. */
+	if (esw->mode == MLX5_ESWITCH_LEGACY)
+		mlx5_eswitch_disable_locked(esw);
 
 	esw->esw_funcs.num_vfs = 0;
 

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -3387,6 +3387,13 @@ static int esw_offloads_stop(struct mlx5_eswitch *esw,
 	int err;
 
 	esw->mode = MLX5_ESWITCH_LEGACY;
+
+	/* If changing from switchdev to legacy mode without sriov enabled,
+	 * no need to create legacy fdb.
+	 */
+	if (!mlx5_sriov_is_enabled(esw->dev))
+		return 0;
+
 	err = mlx5_eswitch_enable_locked(esw, MLX5_ESWITCH_IGNORE_NUM_VFS);
 	if (err)
 		NL_SET_ERR_MSG_MOD(extack, "Failed setting eswitch to legacy");