Hi Piotr, On Fri, Jun 21, 2024 at 02:08:03PM GMT, Piotr Wojtaszczyk wrote: > On Fri, Jun 21, 2024 at 12:57 AM Andi Shyti <andi.shyti@xxxxxxxxxx> wrote: > > On Thu, Jun 20, 2024 at 07:56:41PM GMT, Piotr Wojtaszczyk wrote: > > > When del_timer_sync() is called in an interrupt context it throws a warning > > > because of potential deadlock. Threaded irq handler fixes the potential > > > problem. > > > > > > Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@xxxxxxxxxxx> > > > > did you run into a lockdep splat? > > > > Anything against using del_timer(), instead? Have you tried? > > I didn't get a lockdep splat but console was flooded with warnings from > https://github.com/torvalds/linux/blob/v6.10-rc4/kernel/time/timer.c#L1655 > In the linux kernel v5.15 I didn't see these warnings. > > I'm not a maintainer of the driver and I didn't do any research on > what kind of impact > would have using del_timer() instad. Maybe Vladimir Zapolskiy will know that. Your patch is definitely correct, no doubt about that. And I don't have anything aginast changing irq handlers to threaded handlers. But I would be careful at doing that depending on the use of the controller and for accepting such change I would need an ack from someone who knows the device. Vladimir, perhaps? There are cases where using threaded handlers are not totally right, for example when the controller is used at early boot for power management handling. I don't think it's the case for this driver, but I can't be 100% sure. If you were able to see the flood of WARN_ON's, would be interesting to know how it behaves with del_timer(). Mind giving it a test? Thanks, Andi
