On Sat, 7 Mar 2009, Rafael J. Wysocki wrote: > > One thing about this isn't clear: the distinction between "wake-up" > > interrupts and other interrupts. > > > > In an ideal world, the only pending interrupts during sysdev_suspend > > would be wake-up interrupts, because drivers would have prevented their > > devices from generating any other kind of IRQ and would have done all > > the necessary synchronization as part of their suspend (_not_ > > suspend_late) methods. Thus there would be no need to distinguish > > between wake-up and non-wake-up interrupts. > > > > So perhaps you're worried about drivers that aren't sufficiently > > clever. Or is something deeper going on? > > Some drivers leave interrupts enabled during suspend on purpose and mark > them as "wake-up interrupts" so that the platform can abort suspend if any > of them is pending at the time the "enter suspend" hook is called (this doesn't > happen on x86 AFAICS). > > However, after the $subject patch the CPU will ACK those interrupts if they > happen between suspend_device_irqs() and local_irq_disable(), so the platform > won't see them as pending. Instead, they will have IRQ_PENDING set in > desc->status, so we check if this is the case. You didn't answer my question. Why bother to distinguish between "wake-up" interrupts and non-"wake-up" interrupts? In other words, why not simply abort the suspend if IRQ_PENDING is set for _any_ interrupt during sysdev_suspend()? Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
