Merge commit 'v2.6.31-rc8' into core/locking

Merge reason: we were on -rc4, move to -rc8 before applying
              a new batch of locking infrastructure changes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index c56457c8334..1219be4fb42 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -293,7 +293,12 @@ static inline int clocksource_enable(struct clocksource *cs)
 	if (cs->enable)
 		ret = cs->enable(cs);
 
-	/* save mult_orig on enable */
+	/*
+	 * The frequency may have changed while the clocksource
+	 * was disabled. If so the code in ->enable() must update
+	 * the mult value to reflect the new frequency. Make sure
+	 * mult_orig follows this change.
+	 */
 	cs->mult_orig = cs->mult;
 
 	return ret;
@@ -309,6 +314,13 @@ static inline int clocksource_enable(struct clocksource *cs)
  */
 static inline void clocksource_disable(struct clocksource *cs)
 {
+	/*
+	 * Save mult_orig in mult so clocksource_enable() can
+	 * restore the value regardless if ->enable() updates
+	 * the value of mult or not.
+	 */
+	cs->mult = cs->mult_orig;
+
 	if (cs->disable)
 		cs->disable(cs);
 }