PM / Sleep: Make __pm_stay_awake() delete wakeup source timers
If __pm_stay_awake() is called after __pm_wakeup_event() for the same
wakep source object before its timer expires, it won't cancel the
timer, so the wakeup source will be deactivated from the timer
function as scheduled by __pm_wakeup_event(). In that case
__pm_stay_awake() doesn't have any effect beyond incrementing
the wakeup source's event_count field, although it should cancel
the timer and make the wakeup source stay active until __pm_relax()
is called for it.
To fix this problem make __pm_stay_awake() delete the wakeup source's
timer and ensure that it won't be deactivated from the timer funtion
afterwards by clearing its timer_expires field.
Reported-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index b38bb9a..7c5ab70 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -344,7 +344,6 @@
{
ws->active = true;
ws->active_count++;
- ws->timer_expires = jiffies;
ws->last_time = ktime_get();
/* Increment the counter of events in progress. */
@@ -365,9 +364,14 @@
return;
spin_lock_irqsave(&ws->lock, flags);
+
ws->event_count++;
if (!ws->active)
wakeup_source_activate(ws);
+
+ del_timer(&ws->timer);
+ ws->timer_expires = 0;
+
spin_unlock_irqrestore(&ws->lock, flags);
}
EXPORT_SYMBOL_GPL(__pm_stay_awake);
@@ -541,7 +545,7 @@
if (!expires)
expires = 1;
- if (time_after(expires, ws->timer_expires)) {
+ if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
mod_timer(&ws->timer, expires);
ws->timer_expires = expires;
}