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clockevents: make device shutdown robust

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The device shut down does not cleanup the next_event variable of the
clock event device. So when the device is reactivated the possible
stale next_event value can prevent the device to be reprogrammed as it
claims to wait on a event already.

This is the root cause of the resurfacing suspend/resume problem,
where systems need key press to come back to life.

Fix this by setting next_event to KTIME_MAX when the device is shut
down. Use a separate function for shutdown which takes care of that
and only keep the direct set mode call in the broadcast code, where we
can not touch the next_event value.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner
2008-09-16 11:32:50 -07:00
parent f1926ce63b
commit 2344abbcbd
4 changed files with 19 additions and 8 deletions
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9
kernel/time/tick-broadcast.c
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@@ -236,8 +236,7 @@ static void tick_do_broadcast_on_off(void *why)
if (!cpu_isset(cpu, tick_broadcast_mask)) {
cpu_set(cpu, tick_broadcast_mask);
if (td->mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(dev,
CLOCK_EVT_MODE_SHUTDOWN);
clockevents_shutdown(dev);
}
if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
tick_broadcast_force = 1;
@@ -254,7 +253,7 @@ static void tick_do_broadcast_on_off(void *why)
if (cpus_empty(tick_broadcast_mask)) {
if (!bc_stopped)
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
clockevents_shutdown(bc);
} else if (bc_stopped) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
@@ -306,7 +305,7 @@ void tick_shutdown_broadcast(unsigned int *cpup)
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
if (bc && cpus_empty(tick_broadcast_mask))
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
clockevents_shutdown(bc);
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
@@ -321,7 +320,7 @@ void tick_suspend_broadcast(void)
bc = tick_broadcast_device.evtdev;
if (bc)
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
clockevents_shutdown(bc);
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}