Commit fefa8ff8 authored Jun 18, 2014 by Aaron Plattner Committed by Rafael J. Wysocki Jun 18, 2014

cpufreq: unlock when failing cpufreq_update_policy()

Commit bd0fa9bb introduced a failure path to cpufreq_update_policy() if
cpufreq_driver->get(cpu) returns NULL. However, it jumps to the 'no_policy'
label, which exits without unlocking any of the locks the function acquired
earlier. This causes later calls into cpufreq to hang.

Fix this by creating a new 'unlock' label and jumping to that instead.

Fixes: bd0fa9bb ("cpufreq: Return error if ->get() failed in cpufreq_update_policy()")
Link: https://devtalk.nvidia.com/default/topic/751903/kernel-3-15-and-nv-drivers-337-340-failed-to-initialize-the-nvidia-kernel-module-gtx-550-ti-/

Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 51d211e9

drivers/cpufreq/cpufreq.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -2242,10 +2242,8 @@ int cpufreq_update_policy(unsigned int cpu)
		struct cpufreq_policy new_policy;
		int ret;

		if (!policy) {
		ret = -ENODEV;
		goto no_policy;
		}
		if (!policy)
		return -ENODEV;

		down_write(&policy->rwsem);

		@@ -2264,7 +2262,7 @@ int cpufreq_update_policy(unsigned int cpu)
		new_policy.cur = cpufreq_driver->get(cpu);
		if (WARN_ON(!new_policy.cur)) {
		ret = -EIO;
		goto no_policy;
		goto unlock;
		}

		if (!policy->cur) {
		@@ -2279,10 +2277,10 @@ int cpufreq_update_policy(unsigned int cpu)

		ret = cpufreq_set_policy(policy, &new_policy);

		unlock:
		up_write(&policy->rwsem);

		cpufreq_cpu_put(policy);
		no_policy:
		return ret;
		}
		EXPORT_SYMBOL(cpufreq_update_policy);