diff options
| author | chenqiwu <chenqiwu@xiaomi.com> | 2020-01-07 10:53:19 +0300 |
|---|---|---|
| committer | Viresh Kumar <viresh.kumar@linaro.org> | 2020-01-07 11:01:01 +0300 |
| commit | 8ead819f1befae08182c772b6fdf8ac201b34566 (patch) | |
| tree | 0e72eab18e10d35791a36966e8152faaf6149394 /drivers/cpufreq/s5pv210-cpufreq.c | |
| parent | 83fe39ad0a489200d731c78bfdd40e199e5a9cd2 (diff) | |
| download | linux-8ead819f1befae08182c772b6fdf8ac201b34566.tar.xz | |
cpufreq: s3c: fix unbalances of cpufreq policy refcount
The cpufreq_reboot_notifier_evt() call cpufreq_cpu_get() to get the
cpufreq policy of cpu0, meanwhile, it also increments the kobject
reference count to mark it busy. However, a corresponding call of
cpufreq_cpu_put() is ignored to decrement the kobject reference count
back, which may lead to a potential stuck risk that the cpuhp thread
deadly waits for dropping of kobject refcount when cpufreq policy free.
With this patch, the cpuhp thread can be easily exercised by attempting
to force an unbind of the CPUfreq driver.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/cpufreq/s5pv210-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/s5pv210-cpufreq.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c index 5d10030f2560..e84281e2561d 100644 --- a/drivers/cpufreq/s5pv210-cpufreq.c +++ b/drivers/cpufreq/s5pv210-cpufreq.c @@ -555,8 +555,17 @@ static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this, unsigned long event, void *ptr) { int ret; + struct cpufreq_policy *policy; + + policy = cpufreq_cpu_get(0); + if (!policy) { + pr_debug("cpufreq: get no policy for cpu0\n"); + return NOTIFY_BAD; + } + + ret = cpufreq_driver_target(policy, SLEEP_FREQ, 0); + cpufreq_cpu_put(policy); - ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0); if (ret < 0) return NOTIFY_BAD; |