From 60af1066913162c5dd13fad3b872a67b1eb7da0f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 29 Apr 2012 22:52:34 +0200 Subject: PM / Sleep: Use wait queue to signal "no wakeup events in progress" The current wakeup source deactivation code doesn't do anything when the counter of wakeup events in progress goes down to zero, which requires pm_get_wakeup_count() to poll that counter periodically. Although this reduces the average time it takes to deactivate a wakeup source, it also may lead to a substantial amount of unnecessary polling if there are extended periods of wakeup activity. Thus it seems reasonable to use a wait queue for signaling the "no wakeup events in progress" condition and remove the polling. Signed-off-by: Rafael J. Wysocki Acked-by: mark gross Acked-by: Greg Kroah-Hartman --- drivers/base/power/wakeup.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 2a3e581b8dcd..92f220d89d35 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -17,8 +17,6 @@ #include "power.h" -#define TIMEOUT 100 - /* * If set, the suspend/hibernate code will abort transitions to a sleep state * if wakeup events are registered during or immediately before the transition. @@ -52,6 +50,8 @@ static void pm_wakeup_timer_fn(unsigned long data); static LIST_HEAD(wakeup_sources); +static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); + /** * wakeup_source_prepare - Prepare a new wakeup source for initialization. * @ws: Wakeup source to prepare. @@ -442,6 +442,7 @@ EXPORT_SYMBOL_GPL(pm_stay_awake); */ static void wakeup_source_deactivate(struct wakeup_source *ws) { + unsigned int cnt, inpr; ktime_t duration; ktime_t now; @@ -476,6 +477,10 @@ static void wakeup_source_deactivate(struct wakeup_source *ws) * couter of wakeup events in progress simultaneously. */ atomic_add(MAX_IN_PROGRESS, &combined_event_count); + + split_counters(&cnt, &inpr); + if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) + wake_up(&wakeup_count_wait_queue); } /** @@ -667,14 +672,19 @@ bool pm_wakeup_pending(void) bool pm_get_wakeup_count(unsigned int *count) { unsigned int cnt, inpr; + DEFINE_WAIT(wait); for (;;) { + prepare_to_wait(&wakeup_count_wait_queue, &wait, + TASK_INTERRUPTIBLE); split_counters(&cnt, &inpr); if (inpr == 0 || signal_pending(current)) break; pm_wakeup_update_hit_counts(); - schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT)); + + schedule(); } + finish_wait(&wakeup_count_wait_queue, &wait); split_counters(&cnt, &inpr); *count = cnt; -- cgit v1.2.3