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authorRafael J. Wysocki <rjw@sisk.pl>2012-04-29 22:52:34 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2012-05-01 21:24:59 +0200
commit60af1066913162c5dd13fad3b872a67b1eb7da0f (patch)
treebd2c66ce4c9f78625c018674feedd482a4da97f4 /drivers/base
parent52d136cc2cf6659ee247dbcc88c9e7bd7428ad06 (diff)
downloadop-kernel-dev-60af1066913162c5dd13fad3b872a67b1eb7da0f.zip
op-kernel-dev-60af1066913162c5dd13fad3b872a67b1eb7da0f.tar.gz
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 <rjw@sisk.pl> Acked-by: mark gross <markgross@thegnar.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/wakeup.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 2a3e581..92f220d 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;
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