Tomas, On Thu, Jan 07, 2021 at 04:12:15PM -0800, Guenter Roeck wrote: > Hi, > > On Thu, Jan 07, 2021 at 09:57:30PM +0200, Tomas Winkler wrote: > > From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> > > > > Send the stop command to the firmware on watchdog unregister > > to eleminate false event on suspend. > > > > Normally the watchdog driver would not be expected to unregister > during suspend, only when the driver is manually unloaded. > To support suspend/resume, other watchdog drivers implement > suspend/resume functions to stop the watchdog on suspend and > to restart it on resume. Unloading a watchdog driver on suspend > would also have odd implications for userspace watchdog daemons. > > On top of that, it should not actually be possible to unregister > a watchdog while it is in use (because it is open in that case > and should be marked as busy). watchdog_stop_on_unregister() > only serves as backup in case someone actually manages to unload > the driver while the watchdog is running. The function was > implemented to avoid calls to stop the watchdog in the remove > function because I can not mathematically prove that there are > no situations where the watchdog is unloaded while running. > However, I have not actually been able to do that. > > Are you sure this patch is doing what you expect it to do ? > I have not heard anything back. I tried to understand how this patch would resolve a problem during suspend/resume, but I didn't find anything. Can you maybe add a log message showing the false event that is prevented with this patch, and some context explaining how the patch fixes the problem ? Thanks, Guenter > Thanks, > Guenter > > > Cc: <stable@xxxxxxxxxxxxxxx> > > Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> > > Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx> > > --- > > drivers/watchdog/mei_wdt.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/watchdog/mei_wdt.c b/drivers/watchdog/mei_wdt.c > > index 5391bf3e6b11..c5967d8b4256 100644 > > --- a/drivers/watchdog/mei_wdt.c > > +++ b/drivers/watchdog/mei_wdt.c > > @@ -382,6 +382,7 @@ static int mei_wdt_register(struct mei_wdt *wdt) > > > > watchdog_set_drvdata(&wdt->wdd, wdt); > > watchdog_stop_on_reboot(&wdt->wdd); > > + watchdog_stop_on_unregister(&wdt->wdd); > > > > ret = watchdog_register_device(&wdt->wdd); > > if (ret) > > -- > > 2.26.2 > >
