Re: [PATCH] PM / wakeirq: report wakeup events in dedicated wake-IRQs

[Tony Lindgren]

* Brian Norris <briannorris@xxxxxxxxxxxx> [161110 11:49]:
> On Thu, Nov 10, 2016 at 10:13:55AM -0800, Dmitry Torokhov wrote:
> > On Thu, Nov 10, 2016 at 10:07 AM, Brian Norris <briannorris@xxxxxxxxxxxx> wrote:
> > > It's important that user space can figure out what device woke the
> > > system from suspend -- e.g., for debugging, or for implementing
> > > conditional wake behavior. Dedicated wakeup IRQs don't currently do
> > > that.
> > >
> > > Let's report the event (pm_wakeup_event()) and also allow drivers to
> > > synchronize with these events in their resume path (hence, disable_irq()
> > > instead of disable_irq_nosync()).
> > 
> > Hmm, dev_pm_disable_wake_irq() is called from
> > rpm_suspend()/rpm_resume() that take dev->power.lock spinlock and
> > disable interrupts. Dropping _nosync() feels dangerous.
> 
> Indeed. So how do you suggest we get sane wakeup reports?

__pm_wakeup_event() ?

Tony