diff mbox

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

Message ID 1406910649-4028-2-git-send-email-amit.pundir@linaro.org
State New
Headers show

Commit Message

Amit Pundir Aug. 1, 2014, 4:30 p.m. UTC 
From: Todd Poynor <toddpoynor@google.com>

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@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Len Brown <len.brown@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[Amit Pundir: Reworded the commit message]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
 kernel/irq/pm.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Todd Poynor Aug. 19, 2014, 2:19 a.m. UTC | #1 
On Fri, Aug 1, 2014 at 9:30 AM, Amit Pundir <amit.pundir@linaro.org> wrote:
> From: Todd Poynor <toddpoynor@google.com>
>
> 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.

This info is sometimes useful to debugging Android suspend / battery
life problems, such as to detect a driver that is failing to service
or clear a wakeup interrupt condition.

In general, we intend to fold reporting of suspend abort reasons
(wakeup IRQ pending, wakelock grabbed, task refusing to freeze...)
into the wakeup reason reporting API to userspace previously discussed
on the linux-pm list (and also revive discussion of how to rework that
for mainline acceptance soon).

Thanks,


Todd
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Pavel Machek Aug. 19, 2014, 8:59 a.m. UTC | #2 
On Fri 2014-08-01 22:00:48, Amit Pundir wrote:
> From: Todd Poynor <toddpoynor@google.com>
> 
> 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.
> 

Acked-by: Pavel Machek <pavel@ucw.cz>
diff mbox

Patch

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;
 		}
 		/*