[PATCH 3/3] cpufreq/amd-pstate: Remove warning for X86_FEATURE_CPPC on Zen1 and Zen2

From: Gautham R. Shenoy
Date: Tue Aug 13 2024 - 05:55:56 EST


commit bff7d13c190a ("cpufreq: amd-pstate: add debug message while
CPPC is supported and disabled by SBIOS") issues a warning on plaforms
where the X86_FEATURE_CPPC is expected to be enabled, but is not due
to it being disabled in the BIOS.

This feature bit corresponds to CPUID 0x80000008.ebx[27] which is a
reserved bit on the Zen1 and Zen2 platforms, and is expected to be
cleared on these platforms. Thus printing the warning message for Zen1
and Zen2 models when X86_FEATURE_CPPC is incorrect. Fix this.

Fixes: bff7d13c190a ("cpufreq: amd-pstate: add debug message while CPPC is supported and disabled by SBIOS")
Reported-by: David Wang <00107082@xxxxxxx>
Closes: https://lore.kernel.org/lkml/20240730140111.4491-1-00107082@xxxxxxx/
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
---
drivers/cpufreq/amd-pstate.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 89bda7a2bb8d..66002718397c 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1841,10 +1841,8 @@ static bool amd_cppc_supported(void)
* the code is added for debugging purposes.
*/
if (!cpu_feature_enabled(X86_FEATURE_CPPC)) {
- if (cpu_feature_enabled(X86_FEATURE_ZEN1) || cpu_feature_enabled(X86_FEATURE_ZEN2)) {
- if (c->x86_model > 0x60 && c->x86_model < 0xaf)
- warn = true;
- } else if (cpu_feature_enabled(X86_FEATURE_ZEN3) || cpu_feature_enabled(X86_FEATURE_ZEN4)) {
+ if (cpu_feature_enabled(X86_FEATURE_ZEN3) ||
+ cpu_feature_enabled(X86_FEATURE_ZEN4)) {
if ((c->x86_model > 0x10 && c->x86_model < 0x1F) ||
(c->x86_model > 0x40 && c->x86_model < 0xaf))
warn = true;
--
2.34.1