Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 3/3] PM / Sleep: Make __pm_stay_awake() delete wakeup source timers | Date | Wed, 15 Feb 2012 23:24:07 +0100 |
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From: Rafael J. Wysocki <rjw@sisk.pl>
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.
Conversely, if __pm_wakeup_event() is called for a wakeup source that has been activated by __pm_stay_awake() before, it will set up the timer to deactivate the wakeup source, although it should leave it active until __pm_relax() is called for it.
To fix the first of these problems 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.
To fix the second one, make __pm_wakeup_event() skip setting up the timer if it sees that the wakeup source is active and its timer_expires field is zero, which means that it has been activated by __pm_stay_awake().
Reported-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/wakeup.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
Index: linux/drivers/base/power/wakeup.c =================================================================== --- linux.orig/drivers/base/power/wakeup.c +++ linux/drivers/base/power/wakeup.c @@ -365,9 +365,15 @@ void __pm_stay_awake(struct wakeup_sourc return; spin_lock_irqsave(&ws->lock, flags); + + del_timer(&ws->timer); + ws->timer_expires = 0; + ws->event_count++; + if (!ws->active) wakeup_source_activate(ws); + spin_unlock_irqrestore(&ws->lock, flags); } EXPORT_SYMBOL_GPL(__pm_stay_awake); @@ -529,8 +535,12 @@ void __pm_wakeup_event(struct wakeup_sou spin_lock_irqsave(&ws->lock, flags); ws->event_count++; - if (!ws->active) + if (ws->active) { + if (!ws->timer_expires) + goto unlock; + } else { wakeup_source_activate(ws); + } if (!msec) { wakeup_source_deactivate(ws); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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