Linux Ethernet Bridging - Mar 2022 - [Bridge] [PATCH v2 net-next 2/4] net: switchdev: add support for offloading of fdb locked flag

On ons, mar 23, 2022 at 16:43, Vladimir Oltean <olteanv at gmail.com>
wrote:
> On Wed, Mar 23, 2022 at 01:49:32PM +0100, Hans Schultz wrote:
>> >> Does someone have an idea why there at this point is no option
to add a
>> >> dynamic fdb entry?
>> >> 
>> >> The fdb added entries here do not age out, while the ATU
entries do
>> >> (after 5 min), resulting in unsynced ATU vs fdb.
>> >
>> > I think the expectation is to use br_fdb_external_learn_del() if
the
>> > externally learned entry expires. The bridge should not age by
itself
>> > FDB entries learned externally.
>> >
>> 
>> It seems to me that something is missing then?
>> My tests using trafgen that I gave a report on to Lunn generated
massive
>> amounts of fdb entries, but after a while the ATU was clean and the fdb
>> was still full of random entries...
>
> I'm no longer sure where you are, sorry..
> I think we discussed that you need to enable ATU age interrupts in order
> to keep the ATU in sync with the bridge FDB? Which means either to
> delete the locked FDB entries from the bridge when they age out in the
> ATU, or to keep refreshing locked ATU entries.
> So it seems that you're doing neither of those 2 things if you end up
> with bridge FDB entries which are no longer in the ATU.
Any idea why G2 offset 5 ATUAgeIntEn (bit 10) is set? There is no define
for it, so I assume it is something default?

On Thu, Mar 24, 2022 at 11:32:08AM +0100, Hans Schultz
wrote:
> On ons, mar 23, 2022 at 16:43, Vladimir Oltean <olteanv at gmail.com>
wrote:
> > On Wed, Mar 23, 2022 at 01:49:32PM +0100, Hans Schultz wrote:
> >> >> Does someone have an idea why there at this point is no
option to add a
> >> >> dynamic fdb entry?
> >> >> 
> >> >> The fdb added entries here do not age out, while the ATU
entries do
> >> >> (after 5 min), resulting in unsynced ATU vs fdb.
> >> >
> >> > I think the expectation is to use br_fdb_external_learn_del()
if the
> >> > externally learned entry expires. The bridge should not age
by itself
> >> > FDB entries learned externally.
> >> >
> >> 
> >> It seems to me that something is missing then?
> >> My tests using trafgen that I gave a report on to Lunn generated
massive
> >> amounts of fdb entries, but after a while the ATU was clean and
the fdb
> >> was still full of random entries...
> >
> > I'm no longer sure where you are, sorry..
> > I think we discussed that you need to enable ATU age interrupts in
order
> > to keep the ATU in sync with the bridge FDB? Which means either to
> > delete the locked FDB entries from the bridge when they age out in the
> > ATU, or to keep refreshing locked ATU entries.
> > So it seems that you're doing neither of those 2 things if you end
up
> > with bridge FDB entries which are no longer in the ATU.
> 
> Any idea why G2 offset 5 ATUAgeIntEn (bit 10) is set? There is no define
> for it, so I assume it is something default?
No idea, but I can confirm that the out-of-reset value I see for
MV88E6XXX_G2_SWITCH_MGMT on 6190 and 6390 is 0x400. It's best not to
rely on any reset defaults though.