Re: [PATCH net v2 2/2] net: dsa: mv88e6xxx: flush the ATU when the hash algorithm changes

[Jonas Gorski]

Hi,

On 10/07/2026 01:29, 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.

If changing the algorithm at runtime isn't handled fully and the hw
AFAIU gets out of sync (i.e. static entries get lost from hw, but
retained in the linux bridge), maybe it would make sense to reject
changing it while e.g. a bridge exist?

Feels like an easy foot-gun for hard to debug network issues.

Best regards,
Jonas