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

From: Shuah Khan
Date: Thu Sep 09 2021 - 18:17:01 EST


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@xxxxxxx>
---
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