[lkml]   [2015]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 5/6] watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND
Hi Boris,

I'd missed the fact that this was for SW watchdog as opposed to HW
watchdog, which may explain my confusion.


> > > err = request_irq(wdt->irq, wdt_interrupt,
> >
> > I'm a little confused by this. What happens if the watchdog fires when
> > we're actually in the suspended state (when IRQF_NO_SUSPEND interrupts
> > aren't guaranteed to be delivered).
> It reboot the system.

Is the timer we use to ping the watchdog guaranted to result in a wakeup
before an interrupt will be triggered? If so, then I think we're ok.

If not, then don't we need to clear a potentially pending watchdog irq
at resume time so at to not immediately reboot the machine? I couldn't
see any logic to that effect in the driver.

Regardless, if the only reason we care about taking the interrupt during
the suspend/resume phases is due to the timer sharing the IRQ, then
shouldn't we be using IRQF_COND_SUSPEND?


 \ /
  Last update: 2015-03-05 12:01    [W:0.248 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site