From mboxrd@z Thu Jan 1 00:00:00 1970 From: tglx@linutronix.de (Thomas Gleixner) Date: Wed, 25 Apr 2012 10:50:15 +0200 (CEST) Subject: [PATCH 2/3] IRQ: allow check_wakeup_irqs to notice level-triggered interrupts. In-Reply-To: <20120425030524.7832.85239.stgit@notabene.brown> References: <20120425025637.7832.14013.stgit@notabene.brown> <20120425030524.7832.85239.stgit@notabene.brown> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > --- > > 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