[PATCH v3] cpufreq: s3c: fix unbalances of cpufreq policy refcount

Viresh Kumar viresh.kumar at linaro.org
Tue Jan 7 00:01:45 PST 2020


On 07-01-20, 15:53, qiwuchen55 at gmail.com wrote:
> From: chenqiwu <chenqiwu at xiaomi.com>
> 
> 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 at xiaomi.com>
> ---
> changes in v3:
>  - Rewrite title and commit message.
> ---
>  drivers/cpufreq/s3c2416-cpufreq.c | 12 +++++++++++-
>  drivers/cpufreq/s5pv210-cpufreq.c | 11 ++++++++++-
>  2 files changed, 21 insertions(+), 2 deletions(-)

Applied. Thanks.

-- 
viresh



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