Commit 63c6ba43 authored Aug 15, 2012 by Colin Cross Committed by Rafael J. Wysocki Aug 17, 2012

cpuidle: coupled: fix sleeping while atomic in cpu notifier



The cpu hotplug notifier gets called in both atomic and non-atomic
contexts, it is not always safe to lock a mutex.  Filter out all events
except the six necessary ones, which are all sleepable, before taking
the mutex.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

parent 55d7ec45

drivers/cpuidle/coupled.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -678,6 +678,18 @@ static int cpuidle_coupled_cpu_notify(struct notifier_block *nb,
		int cpu = (unsigned long)hcpu;
		struct cpuidle_device *dev;

		switch (action & ~CPU_TASKS_FROZEN) {
		case CPU_UP_PREPARE:
		case CPU_DOWN_PREPARE:
		case CPU_ONLINE:
		case CPU_DEAD:
		case CPU_UP_CANCELED:
		case CPU_DOWN_FAILED:
		break;
		default:
		return NOTIFY_OK;
		}

		mutex_lock(&cpuidle_lock);

		dev = per_cpu(cpuidle_devices, cpu);