On Wed, Mar 23, 2022 at 11:13:51AM +0100, Hans Schultz wrote: > On tis, mar 22, 2022 at 13:08, Vladimir Oltean <olteanv@xxxxxxxxx> wrote: > > On Tue, Mar 22, 2022 at 12:01:13PM +0100, Hans Schultz wrote: > >> On fre, mar 18, 2022 at 15:19, Vladimir Oltean <olteanv@xxxxxxxxx> wrote: > >> > On Fri, Mar 18, 2022 at 02:10:26PM +0100, Hans Schultz wrote: > >> >> In the offloaded case there is no difference between static and dynamic > >> >> flags, which I see as a general issue. (The resulting ATU entry is static > >> >> in either case.) > >> > > >> > It _is_ a problem. We had the same problem with the is_local bit. > >> > Independently of this series, you can add the dynamic bit to struct > >> > switchdev_notifier_fdb_info and make drivers reject it. > >> > > >> >> These FDB entries are removed when link goes down (soft or hard). The > >> >> zero DPV entries that the new code introduces age out after 5 minutes, > >> >> while the locked flagged FDB entries are removed by link down (thus the > >> >> FDB and the ATU are not in sync in this case). > >> > > >> > Ok, so don't let them disappear from hardware, refresh them from the > >> > driver, since user space and the bridge driver expect that they are > >> > still there. > >> > >> I have now tested with two extra unmanaged switches (each connected to a > >> seperate port on our managed switch, and when migrating from one port to > >> another, there is member violations, but as the initial entry ages out, > >> a new miss violation occurs and the new port adds the locked entry. In > >> this case I only see one locked entry, either on the initial port or > >> later on the port the host migrated to (via switch). > >> > >> If I refresh the ATU entries indefinitly, then this migration will for > >> sure not work, and with the member violation suppressed, it will be > >> silent about it. > > > > Manual says that migrations should trigger miss violations if configured > > adequately, is this not the case? > > > >> So I don't think it is a good idea to refresh the ATU entries > >> indefinitely. > >> > >> Another issue I see, is that there is a deadlock or similar issue when > >> receiving violations and running 'bridge fdb show' (it seemed that > >> member violations also caused this, but not sure yet...), as the unit > >> freezes, not to return... > > > > Have you enabled lockdep, debug atomic sleep, detect hung tasks, things > > like that? > > I have now determined that it is the rtnl_lock() that causes the > "deadlock". The doit() in rtnetlink.c is under rtnl_lock() and is what > takes care of getting the fdb entries when running 'bridge fdb show'. In > principle there should be no problem with this, but I don't know if some > interrupt queue is getting jammed as they are blocked from rtnetlink.c? Sorry, I forgot to respond yesterday to this. By any chance do you maybe have an AB/BA lock inversion, where from the ATU interrupt handler you do mv88e6xxx_reg_lock() -> rtnl_lock(), while from the port_fdb_dump() handler you do rtnl_lock() -> mv88e6xxx_reg_lock()?
