Re: [RFC][PATCH 2/2] PM: Rework handling of interrupts during suspend-resume

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Monday 23 February 2009, Arve Hjønnevåg wrote:
> On Sun, Feb 22, 2009 at 9:39 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> >
> > Introduce two helper functions allowing us to disable device
> > interrupts (at the IO-APIC level) during suspend or hibernation
> > and enable them during the subsequent resume, respectively, so that
> > the timer interrupts are enabled while "late" suspend callbacks 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
> > interrupts will be disabled (at the IO-APIC level), with the help of
> > the new helper function, before calling "late" suspend callbacks
> > provided by device drivers and analogously during resume.
> >
> 
> What impact does this have on wakeup interrupts? Unless you add a
> check, after masking all interrupt at the CPU, to abort suspend if any
> wakeup interrupt has IRQ_PENDING set I think you will loose wakeup
> interrupts (at least for irqs that use default_disable).

I _think_ they would have to be reenabled after we've called
local_irq_disable().

Thanks,
Rafael