[linux-pm] [PATCH 02/10] PM: wakelock: Override wakelocks when not using /sys/power/request_state

[Arve Hjønnevåg]

This preserves existing functionality when CONFIG_WAKELOCK is set.

Signed-off-by: Arve Hjønnevåg <arve at android.com>
---
 include/linux/wakelock.h |    4 ++++
 kernel/power/wakelock.c  |   10 +++++++++-
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/include/linux/wakelock.h b/include/linux/wakelock.h
index ec878d2..af74b65 100755
--- a/include/linux/wakelock.h
+++ b/include/linux/wakelock.h
@@ -72,6 +72,10 @@ int wake_lock_active(struct wake_lock *lock);
  * and non-zero if one or more wake locks are held. Specifically it returns
  * -1 if one or more wake locks with no timeout are active or the
  * number of jiffies until all active wake locks time out.
+ *
+ * To preserve backward compatibility, when the type is WAKE_LOCK_SUSPEND, this
+ * function returns 0 unless it is called during suspend initiated from the
+ * wakelock code.
  */
 long has_wake_lock(int type);
 
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index 13f5d03..c396b58 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -49,6 +49,7 @@ static int current_event_num;
 struct workqueue_struct *suspend_work_queue;
 struct wake_lock main_wake_lock;
 static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
+static bool enable_suspend_wakelocks;
 static struct wake_lock unknown_wakeup;
 
 #ifdef CONFIG_WAKELOCK_STAT
@@ -317,6 +318,9 @@ long has_wake_lock(int type)
 {
 	long ret;
 	unsigned long irqflags;
+	if (WARN_ONCE(type == WAKE_LOCK_SUSPEND && !enable_suspend_wakelocks,
+							"ignoring wakelocks\n"))
+		return 0;
 	spin_lock_irqsave(&list_lock, irqflags);
 	ret = has_wake_lock_locked(type);
 	spin_unlock_irqrestore(&list_lock, irqflags);
@@ -328,10 +332,12 @@ static void suspend_worker(struct work_struct *work)
 	int ret;
 	int entry_event_num;
 
+	enable_suspend_wakelocks = 1;
+
 	if (has_wake_lock(WAKE_LOCK_SUSPEND)) {
 		if (debug_mask & DEBUG_SUSPEND)
 			pr_info("suspend: abort suspend\n");
-		return;
+		goto abort;
 	}
 
 	entry_event_num = current_event_num;
@@ -353,6 +359,8 @@ static void suspend_worker(struct work_struct *work)
 			pr_info("suspend: pm_suspend returned with no event\n");
 		wake_lock_timeout(&unknown_wakeup, HZ / 2);
 	}
+abort:
+	enable_suspend_wakelocks = 0;
 }
 static DECLARE_WORK(suspend_work, suspend_worker);
 
-- 
1.6.1