* Rafael J. Wysocki <raf...@kernel.org> [161111 13:33]: > On Fri, Nov 11, 2016 at 5:31 PM, Tony Lindgren <t...@atomide.com> wrote: > > * Rafael J. Wysocki <raf...@kernel.org> [161110 16:06]: > >> 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? > > > > I guess no other reason except we need to manage the wakeirq > > for rpm_callback(). So we dev_pm_enable_wake_irq() before > > rpm_callback() in rpm_suspend(), then disable on resume. > > But we drop the lock in rpm_callback(), so can't it be moved to where > the callback is invoked?
Then we're back to patching all the drivers again, no? Tony
