From fbd74d16890b9f5d08ea69b5282b123c894f8860 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 13 Jul 2022 12:53:46 -0500 Subject: ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory When commit 72f2ecb7ece7 ("ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported") was introduced, we found collateral damage that a number of AMD systems that supported CPPC but didn't advertise support in _OSC stopped having a functional amd-pstate driver. The _OSC was only enforced on Intel systems at that time. This was fixed for the MSR based designs by commit 8b356e536e69f ("ACPI: CPPC: Don't require _OSC if X86_FEATURE_CPPC is supported") but some shared memory based designs also support CPPC but haven't advertised support in the _OSC. Add support for those designs as well by hardcoding the list of systems. Fixes: 72f2ecb7ece7 ("ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported") Fixes: 8b356e536e69f ("ACPI: CPPC: Don't require _OSC if X86_FEATURE_CPPC is supported") Link: https://lore.kernel.org/all/3559249.JlDtxWtqDm@natalenko.name/ Cc: 5.18+ # 5.18+ Reported-and-tested-by: Oleksandr Natalenko Signed-off-by: Mario Limonciello Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/acpi/cppc.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86') diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index 734b96454896..8d8752b44f11 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -16,6 +16,12 @@ bool cpc_supported_by_cpu(void) switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: case X86_VENDOR_HYGON: + if (boot_cpu_data.x86 == 0x19 && ((boot_cpu_data.x86_model <= 0x0f) || + (boot_cpu_data.x86_model >= 0x20 && boot_cpu_data.x86_model <= 0x2f))) + return true; + else if (boot_cpu_data.x86 == 0x17 && + boot_cpu_data.x86_model >= 0x70 && boot_cpu_data.x86_model <= 0x7f) + return true; return boot_cpu_has(X86_FEATURE_CPPC); } return false; -- cgit v1.2.3