On Sat, 7 Mar 2009, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@xxxxxxx> > > Introduce two helper functions allowing us to prevent device drivers > from getting any interrupts (without disabling interrupts on the CPU) > during suspend (or hibernation) and to make them start to receive > interrupts again during the subsequent resume, respectively. These > functions make it possible to keep timer interrupts enabled while the > "late" suspend and "early" resume callbacks provided by device > drivers are being executed. > > Use these functions to rework the handling of interrupts during > suspend (hibernation) and resume. Namely, interrupts will only be > disabled on the CPU right before suspending sysdevs, while device > drivers will be prevented from receiving interrupts, with the help of > the new helper function, before their "late" suspend callbacks run > (and analogously during resume). > > In addition, since the device interrups are now disabled before the > CPU has turned all interrupts off and the CPU will ACK the interrupts > setting the IRQ_PENDING bit for them, check in sysdev_suspend() if > any wake-up interrupts are pending and abort suspend if that's the > case. 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? Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
