linux-kernel - Re: [PATCH v2 2/2] cpufreq: simplify setpolicy/target check in driver verification

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Message-ID: <20250821091716.x7y76wfvvez6g7el@vireshk-i7>
Date: Thu, 21 Aug 2025 14:47:16 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Zihuan Zhang <zhangzihuan@...inos.cn>
Cc: "rafael J . wysocki" <rafael@...nel.org>,
	zhenglifeng <zhenglifeng1@...wei.com>, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] cpufreq: simplify setpolicy/target check in
 driver verification

On 21-08-25, 17:00, Zihuan Zhang wrote:
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index a067b5447fe8..92633ff2c4f3 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2908,6 +2908,8 @@ static int cpuhp_cpufreq_offline(unsigned int cpu)
>  int cpufreq_register_driver(struct cpufreq_driver *driver_data)
>  {
>  	unsigned long flags;

driver_data can be NULL here. It is checked at a later point.

> +	bool has_setpolicy = driver_data->setpolicy;

This is a pointer and ..

> +	bool has_target = driver_data->target_index || driver_data->target;

.. this is bool.

Their comparison will always fail. Did you actually try this with both
setpolicy and target() set for a cpufreq driver to check if it really
fails ?

What you need is:

	bool has_setpolicy = !!driver_data->setpolicy;

>  	int ret;
>  
>  	if (cpufreq_disabled())
> @@ -2921,10 +2923,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
>  		return -EPROBE_DEFER;
>  
>  	if (!driver_data || !driver_data->verify || !driver_data->init ||
> -	    !(driver_data->setpolicy || driver_data->target_index ||
> -		    driver_data->target) ||
> -	     (driver_data->setpolicy && (driver_data->target_index ||
> -		    driver_data->target)) ||
> +	     (has_setpolicy == has_target) ||

I would rather do:

	(!!driver_data->setpolicy == (driver_data->target_index || driver_data->target))

>  	     (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
>  	     (!driver_data->online != !driver_data->offline) ||
>  		 (driver_data->adjust_perf && !driver_data->fast_switch))
> -- 
> 2.25.1

-- 
viresh