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.
