diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 605656df16c413fd8ed523c672c2713880829693..84f37420fcf544c09e12f730f05a8a85411b36f1 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -173,10 +173,8 @@ static void __clocksource_unstable(struct clocksource *cs)
  * clocksource_mark_unstable - mark clocksource unstable via watchdog
  * @cs:		clocksource to be marked unstable
  *
- * This function is called instead of clocksource_change_rating from
- * cpu hotplug code to avoid a deadlock between the clocksource mutex
- * and the cpu hotplug mutex. It defers the update of the clocksource
- * to the watchdog thread.
+ * This function is called by the x86 TSC code to mark clocksources as unstable;
+ * it defers demotion and re-selection to a kthread.
  */
 void clocksource_mark_unstable(struct clocksource *cs)
 {