From c73c9141d80a5b1a88c59d77abeb0b528c9e0d6f Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Fri, 4 Nov 2011 17:18:21 -0700 Subject: [PATCH] clockevents: Leave the broadcast device in shutdown mode when not needed Platforms with Always Running APIC Timer doesn't use the broadcast timer but the kernel is leaving the broadcast timer (HPET in this case) in oneshot mode. On these platforms, before the switch to oneshot mode, broadcast device is actually in shutdown mode. Code checks for empty tick_broadcast_mask and avoids going into the periodic mode. During switch to oneshot mode, add the same tick_broadcast_mask checks in the tick_broadcast_switch_to_oneshot() and avoid the broadcast device going into the oneshot mode. Signed-off-by: Suresh Siddha Cc: john stultz Cc: venki@google.com Link: http://lkml.kernel.org/r/1320452301.15071.16.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Thomas Gleixner --- kernel/time/tick-broadcast.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index fd4a7b1625a20..e883f57a3cd39 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -575,11 +575,15 @@ void tick_broadcast_switch_to_oneshot(void) unsigned long flags; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); + if (cpumask_empty(tick_get_broadcast_mask())) + goto end; tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT; bc = tick_broadcast_device.evtdev; if (bc) tick_broadcast_setup_oneshot(bc); + +end: raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } -- 2.39.5