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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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32
kernel/time/tick-common.c
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@@ -298,6 +298,28 @@ static void tick_shutdown(unsigned int *cpup)
spin_unlock_irqrestore(&tick_device_lock, flags);
}
static void tick_suspend_periodic(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
spin_lock_irqsave(&tick_device_lock, flags);
if (td->mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
spin_unlock_irqrestore(&tick_device_lock, flags);
}
static void tick_resume_periodic(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
spin_lock_irqsave(&tick_device_lock, flags);
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(td->evtdev, 0);
spin_unlock_irqrestore(&tick_device_lock, flags);
}
/*
* Notification about clock event devices
*/
@@ -325,6 +347,16 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
tick_shutdown(dev);
break;
case CLOCK_EVT_NOTIFY_SUSPEND:
tick_suspend_periodic();
tick_suspend_broadcast();
break;
case CLOCK_EVT_NOTIFY_RESUME:
if (!tick_resume_broadcast())
tick_resume_periodic();
break;
default:
break;
}