Merge commit 'v3.2.9' into rt-3.2.9-rt13v3.2.9-rt13

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index 10a140f82cb8..64483fde95c6 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -865,6 +865,7 @@ static void power_pmu_start(struct perf_event *event, int ef_flags)
 {
 	unsigned long flags;
 	s64 left;
+	unsigned long val;
 
 	if (!event->hw.idx || !event->hw.sample_period)
 		return;
@@ -880,7 +881,12 @@ static void power_pmu_start(struct perf_event *event, int ef_flags)
 
 	event->hw.state = 0;
 	left = local64_read(&event->hw.period_left);
-	write_pmc(event->hw.idx, left);
+
+	val = 0;
+	if (left < 0x80000000L)
+		val = 0x80000000L - left;
+
+	write_pmc(event->hw.idx, val);
 
 	perf_event_update_userpage(event);
 	perf_pmu_enable(event->pmu);