Messages in this thread | | | Date | Mon, 28 Jul 2014 08:51:18 -0700 | From | Sören Brinkmann <> | Subject | Re: [PATCH RFC v2] PM / sleep: Fix racing timers |
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On Mon, 2014-07-28 at 12:05PM +0200, Pavel Machek wrote: > On Fri 2014-07-25 14:06:48, Soren Brinkmann wrote: > > On platforms that do not power off during suspend, successfully entering > > suspend races with timers. > > > > The race happening in a couple of location is: > > > > 1. disable IRQs (e.g. arch_suspend_disable_irqs()) > > ... > > 2. syscore_suspend() > > -> timekeeping_suspend() > > -> clockevents_notify(SUSPEND) > > -> tick_suspend() (timers are turned off here) > > ... > > 3. wfi (wait for wake-IRQ here) > > > > Between steps 1 and 2 the timers can still generate interrupts that are > > not handled and stay pending until step 3. That pending IRQ causes an > > immediate - spurious - wake. > > > > The solution is to move the clockevents suspend/resume notification > > out of the syscore_suspend step and explictly call them at the appropriate > > time in the suspend/hibernation paths. I.e. timers are suspend _before_ > > IRQs get disabled. And accordingly in the resume path. > > > > Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> > > Did you test the hibernation? No, I don't have a system to test hibernation. Suspend seems to work fine though.
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