[PATCH] PM / sleep / irq: Do not suspend wakeup interrupts

From: Rafael J. Wysocki
Date: Thu Jul 10 2014 - 17:19:53 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

If an IRQ has been configured for wakeup via enable_irq_wake(), the
driver who has done that must be prepared for receiving interrupts
after suspend_device_irqs() has returned, so there is no need to
"suspend" such IRQs. Moreover, if drivers using enable_irq_wake()
actually want to receive interrupts after suspend_device_irqs() has
returned, they need to add IRQF_NO_SUSPEND to the IRQ flags while
requesting the IRQs, which shouldn't be necessary (it also goes a bit
too far, as IRQF_NO_SUSPEND causes the IRQ to be ignored by
suspend_device_irqs() all the time regardless of whether or not it
has been configured for signaling wakeup).

For the above reasons, make __disable_irq() ignore IRQ descriptors
with IRQD_WAKEUP_STATE set when its suspend argument is true which
effectively causes them to behave like IRQs with IRQF_NO_SUSPEND
set.

This also allows IRQs configured for wakeup via enable_irq_wake()
to work as wakeup interrupts for the "freeze" (suspend-to-idle)
sleep mode automatically just like for any other sleep states.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
kernel/irq/manage.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-pm/kernel/irq/manage.c
===================================================================
--- linux-pm.orig/kernel/irq/manage.c
+++ linux-pm/kernel/irq/manage.c
@@ -385,7 +385,8 @@ setup_affinity(unsigned int irq, struct
void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
{
if (suspend) {
- if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
+ if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND)
+ || irqd_has_set(&desc->irq_data, IRQD_WAKEUP_STATE))
return;
desc->istate |= IRQS_SUSPENDED;
}

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