Re: [PATCH net-next 3/3] net: dsa: forget the port ageing time when the port leaves the bridge

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Fri, Nov 06, 2026 at 02:30:05PM +0100, Andrew Lunn wrote:
> On Wed, Nov 04, 2026 at 12:48:30PM +0100, Oleksij Rempel wrote:
> > A port that leaves the bridge keeps its cached dp->ageing_time, and it
> > still counts for dsa_switch_fastest_ageing_time(). A port that leaves
> > during an STP topology change keeps the switch at the short value until
> > the port joins a bridge again.
> >
> > Clear the cached value when the port leaves the bridge. The switch is
> > not reprogrammed on leave. If the leaving port held the shortest ageing
> > time, for example during a topology change, the switch keeps that value
> > until the next ageing time change or bridge join in the DSA tree.
>
> Does the software bridge trigger an ageing time change soon
> afterwards?

Only if a topology change is running. Its end is the next change.

> Does a port leaving the software bridge trigger a topology change?

Sometimes, for example when the bridge becomes root afterwards. In my
test it didn't

> I'm just trying to understand how long the fast ageing value will be
> left in place.

With patch 3, until the topology change ends. Without it, until the port
joins a bridge again.

Oleksij