[RFC][PATCH 1/2] PM: Print pending wakeup IRQ preventing suspend to dmesg

[Amit Pundir]

From: Todd Poynor <toddpoynor@xxxxxxxxxx>

Currently when a pending wakeup irq stops suspend, it can be difficult
to determine why suspend was prevented and which IRQ was actually
responsible.

In order to help debug these situations, this patch prints the IRQ
number and action name of that pending wakeup irq which prevents suspend.
This patch comes from the Android patch set, where its been used to debug
suspend problems.

Cc: Pavel Machek <pavel@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: Todd Poynor <toddpoynor@xxxxxxxxxx>
[Amit Pundir: Reworded the commit message]
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
---
 kernel/irq/pm.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index abcd6ca..c2bc8d9 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -109,8 +109,13 @@ int check_wakeup_irqs(void)
 		 * can abort suspend.
 		 */
 		if (irqd_is_wakeup_set(&desc->irq_data)) {
-			if (desc->depth == 1 && desc->istate & IRQS_PENDING)
+			if (desc->depth == 1 && desc->istate & IRQS_PENDING) {
+				pr_info("Wakeup IRQ %d %s pending, suspend aborted\n",
+					irq,
+					desc->action && desc->action->name ?
+					desc->action->name : "");
 				return -EBUSY;
+			}
 			continue;
 		}
 		/*
-- 
1.7.10.4

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