From mboxrd@z Thu Jan 1 00:00:00 1970 From: neilb@suse.de (NeilBrown) Date: Wed, 25 Apr 2012 19:39:16 +1000 Subject: [PATCH 2/3] IRQ: allow check_wakeup_irqs to notice level-triggered interrupts. In-Reply-To: References: <20120425025637.7832.14013.stgit@notabene.brown> <20120425030524.7832.85239.stgit@notabene.brown> Message-ID: <20120425193916.0db1b4b1@notabene.brown> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 25 Apr 2012 10:50:15 +0200 (CEST) Thomas Gleixner wrote: > 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. If there is no handler, then irqd_is_wakeup_set() should fail should it not? For disabled: would it be OK to check desc->depth? Something like: if (desc->depth == 1 && (desc->state & IRQS_SUSPENDED) && irqd_irq_masked(&desc->irq_data)) unmask_irq(desc); ?? Thanks, NeilBrown -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 828 bytes Desc: not available URL: