On Wed, Jun 16, 2021 at 03:59:23PM +0200, Grzegorz Jaszczyk wrote: > On Tue, 15 Jun 2021 at 16:18, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > > > On Tue, Jun 15, 2021 at 02:39:03PM +0200, Grzegorz Jaszczyk wrote: > > > The watchdog drivers often disable wdog clock during suspend and then > > > enable it again during resume. Nevertheless the ping worker is still > > > running and can issue low-level ping while the wdog clock is disabled > > > causing the system hang. To prevent such condition introduce > > > watchdog_dev_suspend/resume which can be used by any wdog driver and > > > actually cancel ping worker during suspend and restore it back, if > > > needed, during resume. > > > > > > > I'll have to look into this further, but I don't think this is the correct > > solution. Most likely the watchdog core needs to have its own independent > > suspend/resule functions and suspend the high resolution timer on > > suspend and restore it on resume. This may require an additional flag > > to be set by drivers to indicate that the timer should be stopped on > > suspend. > > That makes sense - thank you for your suggestion. I think I could > register a pm notifier in the watchdog core when the new e.g. > WDOG_STOP_PING_ON_SUSPEND status flag will be set by the driver and > actually call watchdog_dev_suspend/resume from the notifier callback. > Please let me know if you see any other issue with this solution, if > not I will post v2. > Go for it. Thanks, Guenter
