On Wed, Jan 17, 2024 at 06:44:40AM +0100, Greg Kroah-Hartman wrote: > On Tue, Jan 16, 2024 at 11:40:39PM +0100, Christian A. Ehrhardt wrote: > > Calling ->sync_write must be done while holding the PPM lock as the > > mailbox logic does not support concurrent commands. > > > > Thus protect the only call to ucsi_acknowledge_connector_change > > with the PPM lock as it calls ->sync_write. All other calls to > > ->sync_write already happen under the PPM lock. > > > > Signed-off-by: Christian A. Ehrhardt <lk@xxxxxxx> > > --- > > NOTE: This is not a theoretical issue. I've seen problems resulting > > from the missing lock on real hardware. > > What commit id does this fix? It's hard to tell (due to rewrites, logic and API changes). After digging a bit more I think it is at least a theoretical issues since the introduction of partner tasks. I'll wait a bit for additional feedback and fix this and other issues noticed by your patch bot (sorry for those) in the next iteration. > Should it be cc: stable? Not sure. The race is triggered much more ofter after the quirk added in patch 3/3, so this may not be a practical issue before that. I'll add the tag in the next iteration, though. thanks Christian
