On Thu, Nov 10, 2016 at 01:49:11PM -0700, Tony Lindgren wrote: > * Brian Norris <briannor...@chromium.org> [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 <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? > > __pm_wakeup_event() ?
That's not the difficult part. (This patch already uses pm_wakeup_event() correctly. It's in the ISR, and it doesn't get nested within any other lock-holding code, so it should use the non-underscore version, which grabs the lock.) The difficult part is guaranteeing that the wake IRQ gets reported at the appropriate time. It seems highly unlikely that a threaded IRQ like this would take longer than the time for devices to resume, but it's not guaranteed. So the question is where/when/how we call synchronize_irq(). Brian
