path: root/kernel/time
diff options
authorThomas Gleixner <tglx@linutronix.de>2013-04-25 11:45:53 +0200
committerThomas Gleixner <tglx@linutronix.de>2013-04-25 13:57:04 +0200
commit6f7a05d7018de222e40ca003721037a530979974 (patch)
tree351f0785c033f5c954c8ac67175ccc6524918586 /kernel/time
parent6402c7dc2a19c19bd8cdc7d80878b850da418942 (diff)
clockevents: Set dummy handler on CPU_DEAD shutdown
Vitaliy reported that a per cpu HPET timer interrupt crashes the system during hibernation. What happens is that the per cpu HPET timer gets shut down when the nonboot cpus are stopped. When the nonboot cpus are onlined again the HPET code sets up the MSI interrupt which fires before the clock event device is registered. The event handler is still set to hrtimer_interrupt, which then crashes the machine due to highres mode not being active. See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700333 There is no real good way to avoid that in the HPET code. The HPET code alrady has a mechanism to detect spurious interrupts when event handler == NULL for a similar reason. We can handle that in the clockevent/tick layer and replace the previous functional handler with a dummy handler like we do in tick_setup_new_device(). The original clockevents code did this in clockevents_exchange_device(), but that got removed by commit 7c1e76897 (clockevents: prevent clockevent event_handler ending up handler_noop) which forgot to fix it up in tick_shutdown(). Same issue with the broadcast device. Reported-by: Vitaliy Fillipov <vitalif@yourcmc.ru> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: stable@vger.kernel.org Cc: 700333@bugs.debian.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time')
2 files changed, 5 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 6e23fde83db..61d00a8cdf2 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -66,6 +66,8 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc)
int tick_check_broadcast_device(struct clock_event_device *dev)
+ struct clock_event_device *cur = tick_broadcast_device.evtdev;
if ((dev->features & CLOCK_EVT_FEAT_DUMMY) ||
(tick_broadcast_device.evtdev &&
tick_broadcast_device.evtdev->rating >= dev->rating) ||
@@ -73,6 +75,8 @@ int tick_check_broadcast_device(struct clock_event_device *dev)
return 0;
clockevents_exchange_device(tick_broadcast_device.evtdev, dev);
+ if (cur)
+ cur->event_handler = clockevents_handle_noop;
tick_broadcast_device.evtdev = dev;
if (!cpumask_empty(tick_broadcast_mask))
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 74413e396ac..6176a3e4570 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -323,6 +323,7 @@ static void tick_shutdown(unsigned int *cpup)
clockevents_exchange_device(dev, NULL);
+ dev->event_handler = clockevents_handle_noop;
td->evtdev = NULL;
raw_spin_unlock_irqrestore(&tick_device_lock, flags);