mlxsw: spectrum: Set STP state when leaving 802.1D bridge

When a VLAN device leaves a bridge its STP state is set to DISABLED,
which causes the hardware to discard any packets coming through the port
with this VLAN.

Fix that by setting STP state to FORWARDING when the device leaves its
bridge and allow traffic to be directed to CPU.

Fixes: 26f0e7f ("mlxsw: spectrum: Add support for VLAN devices bridging")
Reported-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2746,6 +2746,13 @@ static int mlxsw_sp_vport_bridge_leave(struct mlxsw_sp_port *mlxsw_sp_vport,
 		goto err_vport_flood_set;
 	}
 
+	err = mlxsw_sp_port_stp_state_set(mlxsw_sp_vport, vid,
+					  MLXSW_REG_SPMS_STATE_FORWARDING);
+	if (err) {
+		netdev_err(dev, "Failed to set STP state\n");
+		goto err_port_stp_state_set;
+	}
+
 	if (flush_fdb && mlxsw_sp_vport_fdb_flush(mlxsw_sp_vport))
 		netdev_err(dev, "Failed to flush FDB\n");
 
@@ -2763,6 +2770,7 @@ static int mlxsw_sp_vport_bridge_leave(struct mlxsw_sp_port *mlxsw_sp_vport,
 
 	return 0;
 
+err_port_stp_state_set:
 err_vport_flood_set:
 err_port_vid_learning_set:
 err_port_vid_to_fid_validate: