From: Suresh Siddha Date: Sat, 5 Nov 2011 00:18:21 +0000 (-0700) Subject: clockevents: Leave the broadcast device in shutdown mode when not needed X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=77b0d60c5adf39c74039e2142a1d3cd1e4d53799;p=linux-beck.git 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 --- diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index fd4a7b1625a2..e883f57a3cd3 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); }