Re: [PATCH 14/19] cpupower: initial AMD P-state capability

Shuah Khan
2021-09-09T22:16:57Z

On 9/8/21 8:59 AM, Huang Rui wrote:
> If kernel enables AMD P-state, cpupower won't need to respond ACPI
> hardware P-states function anymore.
>

This commit log doesn't seem to match the code change. I see it
calling cpupower_amd_pstate_enabled() and setting flags.

> Signed-off-by: Huang Rui <ray.huang@amd.com>
> ---
> tools/power/cpupower/utils/helpers/cpuid.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/tools/power/cpupower/utils/helpers/cpuid.c b/tools/power/cpupower/utils/helpers/cpuid.c
> index 72eb43593180..78218c54acca 100644
> --- a/tools/power/cpupower/utils/helpers/cpuid.c
> +++ b/tools/power/cpupower/utils/helpers/cpuid.c
> @@ -149,6 +149,19 @@ int get_cpu_info(struct cpupower_cpu_info *cpu_info)
> if (ext_cpuid_level >= 0x80000008 &&
> cpuid_ebx(0x80000008) & (1 << 4))
> cpu_info->caps |= CPUPOWER_CAP_AMD_RDPRU;
> +
> + if (cpupower_amd_pstate_enabled(0)) {

What is the reason for calling this function with cpu id = 0?

> + cpu_info->caps |= CPUPOWER_CAP_AMD_PSTATE;
> +
> + /*
> + * If AMD P-state is enabled, the firmware will treat
> + * AMD P-state function as high priority.
> + */
> + cpu_info->caps &= ~CPUPOWER_CAP_AMD_CPB;
> + cpu_info->caps &= ~CPUPOWER_CAP_AMD_CPB_MSR;
> + cpu_info->caps &= ~CPUPOWER_CAP_AMD_HW_PSTATE;
> + cpu_info->caps &= ~CPUPOWER_CAP_AMD_PSTATEDEF;
> + }
> }
>
> if (cpu_info->vendor == X86_VENDOR_INTEL) {
>

thanks,
-- Shuah