Re: [PATCH v10 7/8] cppc_acpi: print error message if CPPC is unsupported

Huang Rui
2024-04-15T15:04:36Z

On Mon, Mar 25, 2024 at 11:03:27AM +0800, Yuan, Perry wrote:
> The amd-pstate driver can fail when _CPC objects are not supported by
> the CPU. However, the current error message is ambiguous (see below) and
> there is no clear way for attributing the failure of the amd-pstate
> driver to the lack of CPPC support.
>
> [ 0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled
>
> Fix this by adding an debug message to notify the user if the amd-pstate
> driver failed to load due to CPPC not be supported by the CPU
>
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
> drivers/acpi/cppc_acpi.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 4bfbe55553f4..3134101f31b6 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -686,8 +686,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
>
> if (!osc_sb_cppc2_support_acked) {
> pr_debug("CPPC v2 _OSC not acked\n");
> - if (!cpc_supported_by_cpu())
> + if (!cpc_supported_by_cpu()) {
> + pr_debug("CPPC is not supported by the CPU\n");
> return -ENODEV;
> + }
> }
>
> /* Parse the ACPI _CPC table for this CPU. */
> --
> 2.34.1
>