Re: [PATCH v3 04/13] cpufreq: amd-pstate: prefetch cppc_req_cached value in amd_pstate_cpu_init()

[Viresh Kumar]

On 12-07-22, 11:40, Perry Yuan wrote:
> This cppc_req_cached valued should be prefetched during
> amd_pstate_cpu_init call period, then the amd_pstate_update() will get
> correct cached value before updating the perf to change the cpu perf
> level.

You are doing more than this in the patch, either mention all the
stuff with reasoning or split into two patches.

> Signed-off-by: Perry Yuan <Perry.Yuan@xxxxxxx>
> ---
>  drivers/cpufreq/amd-pstate.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 43e6df9f67f6..e4904da54541 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -547,12 +547,17 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
>  	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
>  
>  	policy->driver_data = cpudata;
> +	if (!shared_mem) {

This is a new change, which the commit log doesn't talk about.

> +		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_HW_CTL, &value);
> +		if (ret)
> +			return ret;
> +		WRITE_ONCE(cpudata->cppc_hw_conf_cached, value);
>  
> -	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_HW_CTL, &value);
> -	if (ret)
> -		return ret;
> -	WRITE_ONCE(cpudata->cppc_hw_conf_cached, value);
> -
> +		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
> +		if (ret)
> +			return ret;
> +		WRITE_ONCE(cpudata->cppc_req_cached, value);
> +	}
>  	amd_pstate_boost_init(cpudata);
>  
>  	return 0;
> -- 
> 2.25.1

-- 
viresh