Re: [PATCH net v3 2/3] net: dsa: mv88e6xxx: flush the ATU when the hash algorithm changes

[Jonas Gorski]

On Wed, Jul 15, 2026 at 2:08 AM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> On Wed, Jul 15, 2026 at 09:29:42AM +1000, Luke Howard wrote:
> > Changing the ATU hash algorithm invalidates existing entries: those
> > loaded under the previous algorithm end up in different bins and read
> > back corrupted.
> >
> > Flush the ATU whenever the hash algorithm is changed through devlink
> > and reload the default broadcast entries. Per-VLAN ATU entries and
> > any static addresses are not replayed, so the hash must be selected
> > before the FDB or MDB are configured.
>
> Hi Jonas
>
> For v2 you said you thought this was a bit of a foot gun. I suggested
> maybe checking all user ports are admin down. What do you think?

Sorry, saw the email, then completely vanished from my memory.

Probably also needs to be not attached to any bridge, right? To make
sure that no additional static entries can exist (because I think
these are hard to recreate).

AFAICT the default "self" entries probably could be easily
reconstructed since they are just for the ports' mac addresses, so
readding them for all ports that are admin up might be enough.

Best regards,
Jonas