Re: [PATCH net 1/6] net: dsa: ksz: fix FID management

[Vladimir Oltean]

On Wed, Jan 13, 2021 at 01:45:17PM +0100, Gilles DOFFE wrote:
> The FID (Filter ID) is a 7 bits field used to link the VLAN table
> to the static and dynamic mac address tables.
> Until now the KSZ8795 driver could only add one VLAN as the FID was
> always set to 1.

What do you mean the ksz8769 driver could only add one VLAN? That is
obviously a false statement.

All VLANs use the same FID of 1 means that the switch is currently
configured for shared address learning. Whereas each VLAN having a
separate FID would mean that it is configured for individual address
learning.

> This commit allows setting a FID for each new active VLAN.
> The FID list is stored in a static table dynamically allocated from
> ks8795_fid structure.
> Each newly activated VLAN is associated to the next available FID.
> Only the VLAN 0 is not added to the list as it is a special VLAN.
> As it has a special meaning, see IEEE 802.1q.
> When a VLAN is no more used, the associated FID table entry is reset
> to 0.

Why is this patch targeting the "net" tree? What is the problem that it
resolves?