[RFC net-next v2 4/4] Revert "mt7530 mt7530_fdb_write only set ivl bit vid larger than 1"

[DENG Qingfang]

On Mon, Aug 02, 2021 at 04:44:09PM +0300, Vladimir Oltean wrote:
> Would you mind explaining what made VID 1 special in Eric's patch in the
> first place?

The default value of all ports' PVID is 1, which is copied into the FDB
entry, even if the ports are VLAN unaware. So running `bridge fdb show`
will show entries like `dev sw0p0 vlan 1 self` even on a VLAN-unaware
bridge.

Eric probably thought VID 1 is the FDB of all VLAN-unaware bridges, but
that is not true. And his patch probably cause a new issue that FDB is
inaccessible in a VLAN-**aware** bridge with PVID 1.

This series sets PVID to 0 on VLAN-unaware ports, so `bridge fdb show`
will no longer print `vlan 1` on VLAN-unaware bridges, and we don't
need special case in port_fdb_{add,del} for assisted learning.