diff mbox series

[v6,1/6] ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors

Message ID f6ace4124c45e523e984b4eeab3760b95a70b72d.1707363758.git.perry.yuan@amd.com
State New
Headers
Series AMD Pstate Fixes And Enhancements |

Commit Message

Yuan, Perry Feb. 8, 2024, 3:46 a.m. UTC 
  As there are some AMD processors which only support CPPC V2 firmware and
BIOS implementation, the amd_pstate driver will be failed to load when
system booting with below kernel warning message:

[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

To make the amd_pstate driver can be loaded on those TR40 processors, it
needs to match x86_model from 0x30 to 0x7F for family 17H.
With the change, the system can load amd_pstate driver as expected.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reported-by: Gino Badouri <badouri.g@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218171
Fixes: fbd74d1689 ("ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory")
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 arch/x86/kernel/acpi/cppc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Gautham R. Shenoy Feb. 8, 2024, 5:55 a.m. UTC | #1 
Hello Perry,

On Thu, Feb 08, 2024 at 11:46:28AM +0800, Perry Yuan wrote:
> As there are some AMD processors which only support CPPC V2 firmware and
> BIOS implementation, the amd_pstate driver will be failed to load when
> system booting with below kernel warning message:
> 
> [    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled
> 
> To make the amd_pstate driver can be loaded on those TR40 processors, it
> needs to match x86_model from 0x30 to 0x7F for family 17H.
> With the change, the system can load amd_pstate driver as expected.
> 
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> Reported-by: Gino Badouri <badouri.g@gmail.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218171
> Fixes: fbd74d1689 ("ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory")
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> ---
>  arch/x86/kernel/acpi/cppc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
> index 8d8752b44f11..ff8f25faca3d 100644
> --- a/arch/x86/kernel/acpi/cppc.c
> +++ b/arch/x86/kernel/acpi/cppc.c
> @@ -20,7 +20,7 @@ bool cpc_supported_by_cpu(void)
>  		    (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)
> +			 boot_cpu_data.x86_model >= 0x30 && boot_cpu_data.x86_model <= 0x7f)

This looks ok to me.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

--
Thanks and Regards
gautham.
diff mbox series

Patch

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 8d8752b44f11..ff8f25faca3d 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -20,7 +20,7 @@  bool cpc_supported_by_cpu(void)
 		    (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)
+			 boot_cpu_data.x86_model >= 0x30 && boot_cpu_data.x86_model <= 0x7f)
 			return true;
 		return boot_cpu_has(X86_FEATURE_CPPC);
 	}