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authorThomas Gleixner <tglx@linutronix.de>2012-04-25 12:54:54 +0200
committerThomas Gleixner <tglx@linutronix.de>2012-05-04 23:38:50 +0200
commitd4dc0f90d243fb54cfbca6601c9a7c5a758e437f (patch)
treec868d2debe4a4f8d802ad6bbaa257bb5be83dd22 /kernel/irq
parentf5d89470f91f2e67eeaf350c730ae8412c3a98e3 (diff)
downloadlinux-d4dc0f90d243fb54cfbca6601c9a7c5a758e437f.tar.gz
genirq: Allow check_wakeup_irqs to notice level-triggered interrupts
Level triggered interrupts do not cause IRQS_PENDING to be set when
they fire while "disabled" as the 'pending' state is always present in
the level - they automatically refire where re-enabled.

However the IRQS_PENDING flag is also used to abort a suspend cycle -
if any 'is_wakeup_set' interrupt is PENDING, check_wakeup_irqs() will
cause suspend to abort. Without IRQS_PENDING, suspend won't abort.

Consequently, level-triggered interrupts that fire during the 'noirq'
phase of suspend do not currently abort suspend.

So set IRQS_PENDING even for level triggered interrupts, and make sure
to clear the flag in check_irq_resend.

[ Changelog by courtesy of Neil ]

Tested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/chip.c4
-rw-r--r--kernel/irq/resend.c7
2 files changed, 8 insertions, 3 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6080f6bc8c33..741f83643da6 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -379,8 +379,10 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 	 * If its disabled or no action available
 	 * keep it masked and get out of here
 	 */
-	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
+	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
+		desc->istate |= IRQS_PENDING;
 		goto out_unlock;
+	}
 
 	handle_irq_event(desc);
 
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 14dd5761e8c9..6454db7b6a4d 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -58,10 +58,13 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq)
 	/*
 	 * We do not resend level type interrupts. Level type
 	 * interrupts are resent by hardware when they are still
-	 * active.
+	 * active. Clear the pending bit so suspend/resume does not
+	 * get confused.
 	 */
-	if (irq_settings_is_level(desc))
+	if (irq_settings_is_level(desc)) {
+		desc->istate &= ~IRQS_PENDING;
 		return;
+	}
 	if (desc->istate & IRQS_REPLAY)
 		return;
 	if (desc->istate & IRQS_PENDING) {