Re: [PATCH 1/2] acpi: cppc: add cpufreq device

Rafael J. Wysocki
2020-12-10T18:37:01Z

On Thu, Dec 10, 2020 at 3:23 PM Mian Yousaf Kaukab
<yousaf.kaukab@suse.com> wrote:
>
> From: Mian Yousaf Kaukab <ykaukab@suse.de>
>
> Since commit 28f06f770454 ("cppc_cpufreq: replace per-cpu structures with
> lists"), cppc-cpufreq driver doesn't check availability of PSD data before
> registering with cpufreq core. As a result on a ThunderX2 platform when
> CPPC is disabled from BIOS, kernel log is spammed with following messages:
>
> [ 180.974166] CPPC Cpufreq: Error in acquiring _CPC/_PSD data for CPUxx
>
> acpi_cppc_processor_probe() never succeed in this case because
> acpi_evaluate_object_typed("_CPC") always returns AE_NOT_FOUND. When
> cpufreq core calls cppc_cpufreq_cpu_init(), driver fails to obtain PSD data
> and print error messages.
>
> Convert cppc-cpufreq driver to a platform driver (done in a separate patch)
> and add cppc-cpufreq device when acpi_cppc_processor_probe() succeeds.

Honestly, I prefer to drop 28f06f770454 (along with its follower)
instead of making this change.

> Fixes: 28f06f770454 ("cppc_cpufreq: replace per-cpu structures with lists")

Thanks!