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[PATCH] Save/restore periodic tick information over suspend/resume

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The programming of periodic tick devices needs to be saved/restored
across suspend/resume - otherwise we might end up with a system coming
up that relies on getting a PIT (or HPET) interrupt, while those devices
default to 'no interrupts' after powerup. (To confuse things it worked
to a certain degree on some systems because the lapic gets initialized
as a side-effect of SMP bootup.)

This suspend / resume thing was dropped unintentionally during the
last-minute -mm code reshuffling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner
2007-03-06 08:25:42 +01:00
committed by Linus Torvalds
parent c3442e2965
commit 6321dd60c7
4 changed files with 78 additions and 0 deletions
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36
kernel/time/tick-broadcast.c
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@@ -284,6 +284,42 @@ void tick_shutdown_broadcast(unsigned int *cpup)
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
void tick_suspend_broadcast(void)
{
struct clock_event_device *bc;
unsigned long flags;
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
if (bc && tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
int tick_resume_broadcast(void)
{
struct clock_event_device *bc;
unsigned long flags;
int broadcast = 0;
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
if (bc) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC &&
!cpus_empty(tick_broadcast_mask))
tick_broadcast_start_periodic(bc);
broadcast = cpu_isset(smp_processor_id(), tick_broadcast_mask);
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
return broadcast;
}
#ifdef CONFIG_TICK_ONESHOT
static cpumask_t tick_broadcast_oneshot_mask;