From: Ingo Molnar <mingo@elte.hu>

Do not set expires_next to KTIME_MAX if a too short timeout is being set -
this can result in the clock events device being shut down completely.

Found via a stresstest on a C3-lapic-plagued laptop that did very short
sleeps.

This bug could explain the 'Synaptics hang' that was reported.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 kernel/time/clockevents.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff -puN kernel/time/clockevents.c~updated-add-a-framework-to-manage-clock-event-devices-next_event-calculation-fix kernel/time/clockevents.c
--- a/kernel/time/clockevents.c~updated-add-a-framework-to-manage-clock-event-devices-next_event-calculation-fix
+++ a/kernel/time/clockevents.c
@@ -510,10 +510,8 @@ int clockevents_set_next_event(ktime_t e
 	struct clock_event_device *nextevt = devices->nextevt;
 	int64_t delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
 
-	if (delta <= 0 && !force) {
-		devices->expires_next.tv64 = KTIME_MAX;
+	if (delta <= 0 && !force)
 		return -ETIME;
-	}
 
 	devices->expires_next = expires;
 
_