2 files changed, 13 insertions, 22 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 32a895b..2f39a49 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -282,7 +282,7 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
 
 
 extern int clocksource_register(struct clocksource*);
-extern void clocksource_unregister(struct clocksource*);
+extern int clocksource_unregister(struct clocksource*);
 extern void clocksource_touch_watchdog(void);
 extern struct clocksource* clocksource_get_next(void);
 extern void clocksource_change_rating(struct clocksource *cs, int rating);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 791d1ae..31b9033 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -389,28 +389,17 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
 
 static void clocksource_dequeue_watchdog(struct clocksource *cs)
 {
-	struct clocksource *tmp;
 	unsigned long flags;
 
 	spin_lock_irqsave(&watchdog_lock, flags);
-	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
-		/* cs is a watched clocksource. */
-		list_del_init(&cs->wd_list);
-	} else if (cs == watchdog) {
-		/* Reset watchdog cycles */
-		clocksource_reset_watchdog();
-		/* Current watchdog is removed. Find an alternative. */
-		watchdog = NULL;
-		list_for_each_entry(tmp, &clocksource_list, list) {
-			if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY)
-				continue;
-			if (!watchdog || tmp->rating > watchdog->rating)
-				watchdog = tmp;
+	if (cs != watchdog) {
+		if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
+			/* cs is a watched clocksource. */
+			list_del_init(&cs->wd_list);
+			/* Check if the watchdog timer needs to be stopped. */
+			clocksource_stop_watchdog();
 		}
 	}
-	cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
-	/* Check if the watchdog timer needs to be stopped. */
-	clocksource_stop_watchdog();
 	spin_unlock_irqrestore(&watchdog_lock, flags);
 }
 
@@ -841,13 +830,15 @@ static int clocksource_unbind(struct clocksource *cs)
  * clocksource_unregister - remove a registered clocksource
  * @cs:	clocksource to be unregistered
  */
-void clocksource_unregister(struct clocksource *cs)
+int clocksource_unregister(struct clocksource *cs)
 {
+	int ret = 0;
+
 	mutex_lock(&clocksource_mutex);
-	clocksource_dequeue_watchdog(cs);
-	list_del(&cs->list);
-	clocksource_select();
+	if (!list_empty(&cs->list))
+		ret = clocksource_unbind(cs);
 	mutex_unlock(&clocksource_mutex);
+	return ret;
 }
 EXPORT_SYMBOL(clocksource_unregister);