On Fri, Aug 19, 2022 at 06:32:43PM +0200, Takashi Iwai wrote: > Hi, > > we've got multiple reports about 5.19 kernel starting crashing after > some time, and this turned out to be triggered by ucsi_acpi driver. > The details are found in: > https://bugzilla.suse.com/show_bug.cgi?id=1202386 > > The culprit seems to be the commit 87d0e2f41b8c > usb: typec: ucsi: add a common function ucsi_unregister_connectors() Adding Heikki to the thread... > > This commit looks as if it were a harmless cleanup, but this failed in > a subtle way. Namely, in the error scenario, the driver gets an error > at ucsi_register_altmodes(), and goes to the error handling to release > the resources. Through this refactoring, the release part was unified > to a funciton ucsi_unregister_connectors(). And there, it has a NULL > check of con->wq, and it bails out the loop if it's NULL. > Meanwhile, ucsi_register_port() itself still calls destroy_workqueue() > and clear con->wq at its error path. This ended up in the leftover > power supply device with the uninitialized / cleared device. > > It was confirmed that the problem could be avoided by a simple > revert. I'll be glad to revert this now, unless Heikki thinks: > > I guess another fix could be removing the part clearing con->wq, i.e. > > --- a/drivers/usb/typec/ucsi/ucsi.c > +++ b/drivers/usb/typec/ucsi/ucsi.c > @@ -1192,11 +1192,6 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) > out_unlock: > mutex_unlock(&con->lock); > > - if (ret && con->wq) { > - destroy_workqueue(con->wq); > - con->wq = NULL; > - } > - > return ret; > } > > > ... but it's totally untested and I'm not entirely sure whether it's > better. that is any better? thanks, greg k-h
