Re: [PATCH v2 2/2] cpufreq: Serialize global boost updates

[Zhongqiu Han]

On 11/5/2026 5:03 PM, Christian Loehle wrote:
> Serialize concurrent global boost sysfs writes with a mutex.
>
> Fixes: 6f19efc0a1ca ("cpufreq: Add boost frequency support in core")
> Signed-off-by: Christian Loehle <christian.loehle@xxxxxxx>
> Reviewed-by: Pengjie Zhang <zhangpengjie2@xxxxxxxxxx>

The change looks good to me. It might be worth expanding the commit
message a little to describe the race between concurrent global boost
sysfs writes and why serialization is needed.

With that minor comment:

Reviewed-by: Zhongqiu Han <zhongqiu.han@xxxxxxxxxxxxxxxx>

> ---
>   drivers/cpufreq/cpufreq.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 23a77f5524df..d95c849f79c5 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2810,6 +2810,8 @@ int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state)
>   }
>   EXPORT_SYMBOL_GPL(cpufreq_boost_set_sw);
>   
> +static DEFINE_MUTEX(cpufreq_boost_mutex);
> +
>   static int cpufreq_boost_trigger_state(int state)
>   {
>   	struct cpufreq_policy *policy;
> @@ -2817,6 +2819,8 @@ static int cpufreq_boost_trigger_state(int state)
>   	bool boost_enabled;
>   	int ret = -EOPNOTSUPP;
>   
> +	guard(mutex)(&cpufreq_boost_mutex);
> +
>   	/*
>   	 * Don't compare 'cpufreq_driver->boost_enabled' with 'state' here to
>   	 * make sure all policies are in sync with global boost flag.


--
Thx and BRs,
Zhongqiu Han