summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2013-04-25 11:45:53 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 19:57:26 -0700
commita35089a9cc44f621e58af899b3483d206bb89284 (patch)
tree7a2af2c4383cb856bf048bd8d1efe1a057230b06
parented0a169166af3fc21e3b8ee9f3020298a93f9bd7 (diff)
downloadlwn-a35089a9cc44f621e58af899b3483d206bb89284.tar.gz
lwn-a35089a9cc44f621e58af899b3483d206bb89284.zip
clockevents: Set dummy handler on CPU_DEAD shutdown
commit 6f7a05d7018de222e40ca003721037a530979974 upstream. 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: 700333@bugs.debian.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/time/tick-broadcast.c4
-rw-r--r--kernel/time/tick-common.c1
2 files changed, 5 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 9e40370c7695..e9df75d22436 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_get_broadcast_mask()))
tick_broadcast_start_periodic(dev);
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 119528de8235..c43b479c908e 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -323,6 +323,7 @@ static void tick_shutdown(unsigned int *cpup)
*/
dev->mode = CLOCK_EVT_MODE_UNUSED;
clockevents_exchange_device(dev, NULL);
+ dev->event_handler = clockevents_handle_noop;
td->evtdev = NULL;
}
raw_spin_unlock_irqrestore(&tick_device_lock, flags);