Messages in this thread | | | Date | Mon, 5 Feb 2024 10:26:52 -0600 | Subject | Re: [PATCH v3 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing | From | Mario Limonciello <> |
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On 2/4/2024 20:29, Yuan, Perry wrote: > [AMD Official Use Only - General] > >> -----Original Message----- >> From: Oleksandr Natalenko <oleksandr@natalenko.name> >> Sent: Sunday, February 4, 2024 10:45 PM >> To: rafael.j.wysocki@intel.com; Limonciello, Mario >> <Mario.Limonciello@amd.com>; viresh.kumar@linaro.org; Huang, Ray >> <Ray.Huang@amd.com>; Shenoy, Gautham Ranjal >> <gautham.shenoy@amd.com>; Petkov, Borislav >> <Borislav.Petkov@amd.com>; Yuan, Perry <Perry.Yuan@amd.com> >> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Huang, Shimmer >> <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, >> Li (Jassmine) <Li.Meng@amd.com>; linux-pm@vger.kernel.org; linux- >> kernel@vger.kernel.org >> Subject: Re: [PATCH v3 6/6] cpufreq:amd-pstate: add quirk for the pstate >> CPPC capabilities missing >> >> Hello. >> >> On neděle 4. února 2024 4:26:14 CET Perry Yuan wrote: >>> Add quirks table to get CPPC capabilities issue fixed by providing >>> correct perf or frequency values while driver loading. >>> >>> If CPPC capabilities are not defined in the ACPI tables or wrongly >>> defined by platform firmware, it needs to use quick to get those >>> issues fixed with correct workaround values to make pstate driver can >>> be loaded even though there are CPPC capabilities errors. >>> >>> The workaround will match the broken BIOS which lack of CPPC >>> capabilities nominal_freq and lowest_freq definition in the ACPI table. >>> >>> $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq >>> 0 >>> $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq >>> 0 >>> >>> Signed-off-by: Perry Yuan <perry.yuan@amd.com> >>> --- >>> drivers/cpufreq/amd-pstate.c | 49 >> ++++++++++++++++++++++++++++++++++-- >>> include/linux/amd-pstate.h | 6 +++++ >>> 2 files changed, 53 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/cpufreq/amd-pstate.c >>> b/drivers/cpufreq/amd-pstate.c index 77effc3caf6c..25a6d8a808c4 100644 >>> --- a/drivers/cpufreq/amd-pstate.c >>> +++ b/drivers/cpufreq/amd-pstate.c >>> @@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver; >>> static int cppc_state = AMD_PSTATE_UNDEFINED; static bool >>> cppc_enabled; static bool amd_pstate_prefcore = true; >>> +static struct quirk_entry *quirks; >>> >>> /* >>> * AMD Energy Preference Performance (EPP) @@ -111,6 +112,33 @@ >>> static unsigned int epp_values[] = { >>> >>> typedef int (*cppc_mode_transition_fn)(int); >>> >>> +static struct quirk_entry quirk_amd_7k62 = { >>> + .nominal_freq = 2600, >>> + .lowest_freq = 550, >>> +}; >>> + >>> +static int __init dmi_matched(const struct dmi_system_id *dmi) { >>> + quirks = dmi->driver_data; >>> + pr_info("hardware type %s found\n", dmi->ident); >>> + >>> + return 1; >>> +} >>> + >>> +static const struct dmi_system_id amd_pstate_quirks_table[] __initconst >> = { >>> + { >>> + .callback = dmi_matched, >>> + .ident = "AMD EPYC 7K62", >>> + .matches = { >>> + DMI_MATCH(DMI_BIOS_VERSION, "5.14"), >>> + DMI_MATCH(DMI_BIOS_RELEASE, "12/12/2019"); >> >> I think this is incorrect, and there should be a comma "," instead of >> semicolon ";" at the end of the string. Otherwise the build will fail. > > Good catch, I made a mistake here, I found this after I sent it out, have it fixed in V4. > Thanks for the review.
I'm still wondering if this is the right level of narrowness. Does the quirk only apply to a single BIOS vendor? Or any other sysfs attributes that can be generic to all affected systems?
Also would it perhaps make sense to rename dmi_matched to dmi_matched_7k62_bios_bug and then in dmi_matched_7k62_bios_bug check the model/family match. In that function you can only set quirks = dmi->driver_data
If the right CPU applies then too.
> > Perry. > >> >>> + }, >>> + .driver_data = &quirk_amd_7k62, >>> + }, >>> + {} >>> +}; >>> +MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table); >>> + >>> static inline int get_mode_idx_from_str(const char *str, size_t size) >>> { >>> int i; >>> @@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned int >>> cpu, static int amd_get_min_freq(struct amd_cpudata *cpudata) { >>> struct cppc_perf_caps cppc_perf; >>> + u32 lowest_freq; >>> >>> int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); >>> if (ret) >>> return ret; >>> >>> + if (quirks && quirks->lowest_freq) >>> + lowest_freq = quirks->lowest_freq; >>> + else >>> + lowest_freq = cppc_perf.lowest_freq; >>> + >>> /* Switch to khz */ >>> - return cppc_perf.lowest_freq * 1000; >>> + return lowest_freq * 1000; >>> } >>> >>> static int amd_get_max_freq(struct amd_cpudata *cpudata) @@ -635,12 >>> +669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata) >>> static int amd_get_nominal_freq(struct amd_cpudata *cpudata) { >>> struct cppc_perf_caps cppc_perf; >>> + u32 nominal_freq; >>> >>> int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); >>> if (ret) >>> return ret; >>> >>> - return cppc_perf.nominal_freq; >>> + if (quirks && quirks->nominal_freq) >>> + nominal_freq = quirks->nominal_freq; >>> + else >>> + nominal_freq = cppc_perf.nominal_freq; >>> + >>> + return nominal_freq; >>> } >>> >>> static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) >>> @@ -1672,6 +1712,11 @@ static int __init amd_pstate_init(void) >>> if (cpufreq_get_current_driver()) >>> return -EEXIST; >>> >>> + quirks = NULL; >>> + >>> + /* check if this machine need CPPC quirks */ >>> + dmi_check_system(amd_pstate_quirks_table); >>> + >>> switch (cppc_state) { >>> case AMD_PSTATE_UNDEFINED: >>> /* Disable on the following configs by default: >>> diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h >>> index d21838835abd..7b2cbb892fd9 100644 >>> --- a/include/linux/amd-pstate.h >>> +++ b/include/linux/amd-pstate.h >>> @@ -124,4 +124,10 @@ static const char * const >> amd_pstate_mode_string[] = { >>> [AMD_PSTATE_GUIDED] = "guided", >>> NULL, >>> }; >>> + >>> +struct quirk_entry { >>> + u32 nominal_freq; >>> + u32 lowest_freq; >>> +}; >>> + >>> #endif /* _LINUX_AMD_PSTATE_H */ >>> >> >> >> -- >> Oleksandr Natalenko (post-factum)
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