linux-kernel - Re: [PATCH v11 6/9] cpufreq: amd-pstate: Add set

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Message-ID: <aa2f473c-38e3-44a6-a039-99b42d9a51d0@amd.com>
Date: Thu, 13 Jun 2024 12:52:32 -0500
From: Mario Limonciello <mario.limonciello@....com>
To: Perry Yuan <perry.yuan@....com>, gautham.shenoy@....com,
 Borislav.Petkov@....com
Cc: rafael.j.wysocki@...el.com, viresh.kumar@...aro.org,
 Alexander.Deucher@....com, Xinmei.Huang@....com, Xiaojian.Du@....com,
 Li.Meng@....com, linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v11 6/9] cpufreq: amd-pstate: Add set_boost callback for
 active mode

On 6/13/2024 02:25, Perry Yuan wrote:
> Add support for the set_boost callback in the active mode driver to
> enable boost control via the cpufreq core. This ensures a consistent
> boost control interface across all pstate modes, including passive
> mode, guided mode, and active mode.
> 
> With this addition, all three pstate modes can support the same boost
> control interface with unique interface and global CPB control. Each
> CPU also supports individual boost control, allowing global CPB to
> change all cores' boost states simultaneously. Specific CPUs can
> update their boost states separately, ensuring all cores' boost
> states are synchronized.
> 
> Signed-off-by: Perry Yuan <perry.yuan@....com>
> ---
>   drivers/cpufreq/amd-pstate.c | 18 +++++-------------
>   1 file changed, 5 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index fe7c9d3562c5..d07f09dd7eab 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -701,20 +701,11 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
>   		pr_err("Boost mode is not supported by this processor or SBIOS\n");
>   		return -ENOTSUPP;
>   	}
> +	mutex_lock(&amd_pstate_driver_lock);
> +	ret = amd_pstate_cpu_boost(policy->cpu, state);
> +	mutex_unlock(&amd_pstate_driver_lock);
>   
> -	if (state)
> -		policy->cpuinfo.max_freq = cpudata->max_freq;
> -	else
> -		policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
> -
> -	policy->max = policy->cpuinfo.max_freq;
> -
> -	ret = freq_qos_update_request(&cpudata->req[1],
> -				      policy->cpuinfo.max_freq);
> -	if (ret < 0)
> -		return ret;
> -
> -	return 0;
> +	return ret < 0 ? ret : 0;

What's wrong with just doing this instead:

return ret;

>   }
>   
>   static int amd_pstate_boost_set(struct amd_cpudata *cpudata)
> @@ -1875,6 +1866,7 @@ static struct cpufreq_driver amd_pstate_epp_driver = {
>   	.resume		= amd_pstate_epp_resume,
>   	.update_limits	= amd_pstate_update_limits,
>   	.init_boost	= amd_pstate_init_boost,
> +	.set_boost	= amd_pstate_set_boost,
>   	.name		= "amd-pstate-epp",
>   	.attr		= amd_pstate_epp_attr,
>   };