From 378eef99ad45700aabfba2bd962516e5608b259a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 31 Jan 2011 11:06:50 +0100 Subject: [PATCH] PM / Wakeup: Make pm_save_wakeup_count() work as documented According to Documentation/ABI/testing/sysfs-power, the /sys/power/wakeup_count interface should only make the kernel react to wakeup events during suspend if the last write to it has been successful. However, if /sys/power/wakeup_count is written to two times in a row, where the first write is successful and the second is not, the kernel will still react to wakeup events during suspend due to a bug in pm_save_wakeup_count(). Fix the bug by making pm_save_wakeup_count() clear events_check_enabled unconditionally before checking if there are any new wakeup events registered since the previous read from /sys/power/wakeup_count. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeup.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index e5e73b5efc80..07e08c3aece4 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -616,25 +616,25 @@ bool pm_get_wakeup_count(unsigned int *count) * * If @count is equal to the current number of registered wakeup events and the * current number of wakeup events being processed is zero, store @count as the - * old number of registered wakeup events to be used by pm_check_wakeup_events() - * and return true. Otherwise return false. + * old number of registered wakeup events for pm_check_wakeup_events(), enable + * wakeup events detection and return 'true'. Otherwise disable wakeup events + * detection and return 'false'. */ bool pm_save_wakeup_count(unsigned int count) { unsigned int cnt, inpr; - bool ret = false; + events_check_enabled = false; spin_lock_irq(&events_lock); split_counters(&cnt, &inpr); if (cnt == count && inpr == 0) { saved_count = count; events_check_enabled = true; - ret = true; } spin_unlock_irq(&events_lock); - if (!ret) + if (!events_check_enabled) pm_wakeup_update_hit_counts(); - return ret; + return events_check_enabled; } static struct dentry *wakeup_sources_stats_dentry; -- 2.20.1