This is a note to let you know that I've just added the patch titled ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: acpi-cppc-enable-amd-cppc-v2-support-for-family-17h-.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 119bcc7b5f95ac288765cb98874eda2f0ccc9c33 Author: Perry Yuan <perry.yuan@xxxxxxx> Date: Thu Feb 8 11:46:28 2024 +0800 ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors [ Upstream commit a51ab63b297ce9e26e3ffb9be896018a42d5f32f ] 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@xxxxxxx> Reported-by: Gino Badouri <badouri.g@xxxxxxxxx> 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@xxxxxxx> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index 8d8752b44f113..ff8f25faca3dd 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); }