bridge: switchdev: Offload VLAN flags to hardware bridge

When VLANs are created / destroyed on a VLAN filtering bridge (MASTER
flag set), the configuration is passed down to the hardware. However,
when only the flags (e.g. PVID) are toggled, the configuration is done
in the software bridge alone.

While it is possible to pass these flags to hardware when invoked with
the SELF flag set, this creates inconsistency with regards to the way
the VLANs are initially configured.

Pass the flags down to the hardware even when the VLAN already exists
and only the flags are toggled.

Signed-off-by: Ido Schimmel <[e-mail]>
Signed-off-by: Jiri Pirko <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/bridge/br_vlan.c

···
  */
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 {
+	struct switchdev_obj_port_vlan v = {
+		.obj.orig_dev = port->dev,
+		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+		.flags = flags,
+		.vid_begin = vid,
+		.vid_end = vid,
+	};
 	struct net_bridge_vlan *vlan;
 	int ret;
 
···
 
 	vlan = br_vlan_find(nbp_vlan_group(port), vid);
 	if (vlan) {
+		/* Pass the flags to the hardware bridge */
+		ret = switchdev_port_obj_add(port->dev, &v.obj);
+		if (ret && ret != -EOPNOTSUPP)
+			return ret;
 		__vlan_add_flags(vlan, flags);
 		return 0;
 	}