Re: [PATCH] cpufreq: amd-pstate: Add resume and suspend callback for amd-pstate

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Jun 23, 2022 at 11:15:09AM +0800, Jinzhou Su wrote:
> When system resumes from S3, the CPPC enable register will be
> cleared and reset to 0. So sets this bit to enable CPPC
> interface by writing 1 to this register.
> 
> Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 7be38bc6a673..9ac75c1cde9c 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -566,6 +566,28 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
>  	return 0;
>  }
>  
> +static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
> +{
> +	int ret;
> +
> +	ret = amd_pstate_enable(true);
> +	if (ret)
> +		pr_err("failed to enable amd-pstate during resume, return %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
> +{
> +	int ret;
> +
> +	ret = amd_pstate_enable(false);
> +	if (ret)
> +		pr_err("failed to disable amd-pstate during suspend, return %d\n", ret);
> +
> +	return ret;
> +}
> +
>  /* Sysfs attributes */
>  
>  /*
> @@ -636,6 +658,8 @@ static struct cpufreq_driver amd_pstate_driver = {
>  	.target		= amd_pstate_target,
>  	.init		= amd_pstate_cpu_init,
>  	.exit		= amd_pstate_cpu_exit,
> +	.suspend	= amd_pstate_cpu_suspend,
> +	.resume		= amd_pstate_cpu_resume,
>  	.set_boost	= amd_pstate_set_boost,
>  	.name		= "amd-pstate",
>  	.attr           = amd_pstate_attr,
> -- 
> 2.32.0
> 

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>