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| author | Mario Limonciello <mario.limonciello@amd.com> | 2022-07-05 21:29:15 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-07-05 21:36:11 +0300 |
| commit | 8b356e536e69f3a4d6778ae9f0858a1beadabb1f (patch) | |
| tree | d94dad9bd21c339a808f95f19da24175ea79049b /drivers/acpi/cppc_acpi.c | |
| parent | 7feec7430edddb87c24b0a86b08a03d0b496a755 (diff) | |
| download | linux-8b356e536e69f3a4d6778ae9f0858a1beadabb1f.tar.xz | |
ACPI: CPPC: Don't require _OSC if X86_FEATURE_CPPC is supported
commit 72f2ecb7ece7 ("ACPI: bus: Set CPPC _OSC bits for all and
when CPPC_LIB is supported") added support for claiming to
support CPPC in _OSC on non-Intel platforms.
This unfortunately caused a regression on a vartiety of AMD
platforms in the field because a number of AMD platforms don't set
the `_OSC` bit 5 or 6 to indicate CPPC or CPPC v2 support.
As these AMD platforms already claim CPPC support via a dedicated
MSR from `X86_FEATURE_CPPC`, use this enable this feature rather
than requiring the `_OSC` on platforms with a dedicated MSR.
If there is additional breakage on the shared memory designs also
missing this _OSC, additional follow up changes may be needed.
Fixes: 72f2ecb7ece7 ("Set CPPC _OSC bits for all and when CPPC_LIB is supported")
Reported-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
| -rw-r--r-- | drivers/acpi/cppc_acpi.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index d64facbda0fb..6ff1901d7d43 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -578,6 +578,19 @@ bool __weak cpc_ffh_supported(void) } /** + * cpc_supported_by_cpu() - check if CPPC is supported by CPU + * + * Check if the architectural support for CPPC is present even + * if the _OSC hasn't prescribed it + * + * Return: true for supported, false for not supported + */ +bool __weak cpc_supported_by_cpu(void) +{ + return false; +} + +/** * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace * * Check and allocate the cppc_pcc_data memory. @@ -686,7 +699,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) if (!osc_sb_cppc2_support_acked) { pr_debug("CPPC v2 _OSC not acked\n"); - return -ENODEV; + if (!cpc_supported_by_cpu()) + return -ENODEV; } /* Parse the ACPI _CPC table for this CPU. */ |