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authorThomas Gleixner <tglx@linutronix.de>2007-03-06 08:25:42 +0100
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-06 09:30:24 -0800
commit6321dd60c76b2e12383bc06046288b15397ed3a0 (patch)
tree4cea63e69ce4f6f5f7f94fc6905063efdde7974e /kernel/time/tick-common.c
parentc3442e296517aee733d62fc3fe03211598902c7d (diff)
[PATCH] Save/restore periodic tick information over suspend/resume
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>
Diffstat (limited to 'kernel/time/tick-common.c')
-rw-r--r--kernel/time/tick-common.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 0986a2bfab4..43ba1bdec14 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -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;
}