On Thu, Nov 10, 2016 at 7:49 PM, Brian Norris <briannor...@chromium.org> wrote: > On Thu, Nov 10, 2016 at 10:13:55AM -0800, Dmitry Torokhov wrote: >> On Thu, Nov 10, 2016 at 10:07 AM, Brian Norris <briannor...@chromium.org> >> 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? Every device > or bus that's going to use the dedicated wake APIs has to > synchronize_irq() [1] in their resume() routine? Seems like an odd > implementation detail to have to remember (and therefore most drivers > will get it wrong). > > Brian > > [1] Or maybe at least create a helper API that will extract the > dedicated wake IRQ number and do the synchronize_irq() for us, so > drivers don't have to stash this separately (or poke at > dev->power.wakeirq->irq) for no good reason.
Well, in the first place, can anyone please refresh my memory on why it is necessary to call dev_pm_disable_wake_irq() under power.lock? Thanks, Rafael
