[PATCH] PM: wakeup: Wakeup accounting for interrupts

[Loic Poulain <loic.poulain@linaro.org>]

Most of the time, system wakeup is caused by a wakeup-enabled
interrupt, but the accounting is not done for the related wakeup
source, causing wrong values reported by device's wakeup attributes
and debugfs stats (debug/wakeup_sources).

This change reports a wakeup event for any wakeup-sources the irq is
attached with.

Note: This only works for drivers explicitly attaching the irq to
a given device (e.g. with dev_pm_set_wake_irq).

Note2: Some drivers call pm_wakeup_event() in their irq handler, but
not all, moreover, an interrupt can be disabled while being flagged
as wakeup source, and so accounting must be performed. This solution
ensures that accounting will always be done for the interrupt waking
up the host.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
---
 drivers/base/power/wakeup.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index f0b37c1..922f701 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -952,8 +952,19 @@ void pm_wakeup_clear(bool reset)
 void pm_system_irq_wakeup(unsigned int irq_number)
 {
 	if (pm_wakeup_irq == 0) {
+		struct wakeup_source *ws;
+		int srcuidx;
+
 		pm_wakeup_irq = irq_number;
 		pm_system_wakeup();
+
+		/* wakeup accounting */
+		srcuidx = srcu_read_lock(&wakeup_srcu);
+		list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
+			if (ws->wakeirq && ws->wakeirq->irq == irq_number)
+				pm_wakeup_ws_event(ws, 0, false);
+		}
+		srcu_read_unlock(&wakeup_srcu, srcuidx);
 	}
 }
 
-- 
2.7.4