| Message ID | 20240813095459.2122-1-gautham.shenoy@amd.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | Mario Limonciello |
| Headers | show |
| Series | cpufreq/amd-pstate: A set of fixes | expand |
Hi Gautham, On 2024/8/13 17:54, Gautham R. Shenoy wrote: > ... > > 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. > > ... > 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; Some models of ZEN2 APU/CPU require this warning info, like Renoir (Ryzen 7 4800H mobile APU/4750G desktop APU, Ryzen 5 4600 desktop CPU), Lucienne (Ryzen 5 5500U mobile APU) and Aerith (APU of Steam Deck console). So it has to use model ID to narrow down the coverage. For ZEN1 APU/CPU, this warning can be removed completely, because ZEN1 doesn't support CPPC. Thanks, Xiaojian > - } 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;
Hello Xiaojian, On Wed, Aug 14, 2024 at 05:29:04PM +0800, Xiaojian Du wrote: > Hi Gautham, > > On 2024/8/13 17:54, Gautham R. Shenoy wrote: > > ... > > > > 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. > > > > ... > > 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; > > Some models of ZEN2 APU/CPU require this warning info, like Renoir (Ryzen 7 > 4800H mobile APU/4750G desktop APU, > Ryzen 5 4600 desktop CPU), Lucienne (Ryzen 5 5500U mobile APU) and Aerith > (APU of Steam Deck console). > > So it has to use model ID to narrow down the coverage. > I checked the publicly available PPRs of the Family 17h models 0x60 (Renoir) [1] and Family 17h model 0x71 (Matisse) [2]. In both these PPRs, CPUID 0x80000008 EBX[27] is a reserved bit. In fact, David reported this issue on Matisse system. I am happy to retain the warnings for specific models which are known to have support for the CPPC MSRs (which is what CPUID 0x80000008 EBX[27] advertises). Could you please share the model numbers of those that you are aware of? [1] PPR Family 17h Model 0x60 : https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/55922-A1-PUB.zip [2] PPR Family 17h Model 0x71 : https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/56176_ppr_Family_17h_Model_71h_B0_pub_Rev_3_06.zip > For ZEN1 APU/CPU, this warning can be removed completely, because ZEN1 > doesn't support CPPC. Agreed. > > Thanks, > Xiaojian -- Thanks and Regards gautham.
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;
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@163.com> Closes: https://lore.kernel.org/lkml/20240730140111.4491-1-00107082@163.com/ Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com> --- drivers/cpufreq/amd-pstate.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)