Messages in this thread | | | Date | Wed, 25 Apr 2012 10:50:15 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 2/3] IRQ: allow check_wakeup_irqs to notice level-triggered interrupts. |
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On Wed, 25 Apr 2012, NeilBrown wrote:
> Level triggered interrupts do not cause IRQS_PENDING to be set, so > check_wakeup_irqs ignores them. > They don't need to set IRQS_PENDING as the level stays high which > shows that they must be pending. However if such an interrupt fired > during late suspend, it will have been masked so the fact that it > is still asserted will not cause the suspend to abort. > > So if any wakeup interrupt is masked, unmask it when checking wakeup > irqs. If the interrupt is asserted, suspend will abort. > > Signed-off-by: NeilBrown <neilb@suse.de> > --- > > kernel/irq/pm.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c > index 15e53b1..0d26206 100644 > --- a/kernel/irq/pm.c > +++ b/kernel/irq/pm.c > @@ -106,6 +106,12 @@ int check_wakeup_irqs(void) > if (irqd_is_wakeup_set(&desc->irq_data)) { > if (desc->istate & IRQS_PENDING) > return -EBUSY; > + if (irqd_irq_masked(&desc->irq_data)) > + /* Probably a level interrupt > + * which fired recently and was > + * masked > + */ > + unmask_irq(desc);
Oh no. We don't unmask unconditionally. What about an interrupt which is disabled, has no handler ..... ? That needs more thought.
Thanks,
tglx
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