Re: [PATCH v8 0/7] Enhanced autonomous selection and improvements

[Sumit Gupta <sumitg@nvidia.com>]

On 28/02/26 02:06, Rafael J. Wysocki wrote:
> External email: Use caution opening links or attachments
>
>
> On Thu, Feb 26, 2026 at 2:59 PM Sumit Gupta <sumitg@nvidia.com> wrote:
>>
>>> This patch series improves the CPPC cpufreq driver with new ACPI APIs
>>> and enhancements for Autonomous Selection (auto_select).
>>>
>>> CPPC auto_select enables hardware-driven CPU performance scaling using
>>> Energy Performance Preference (EPP) hints. Currently, there's limited
>>> runtime control and visibility into CPPC performance registers.
>>>
>>> The series adds cppc_get_perf() API to read performance controls, updates
>>> MIN_PERF/MAX_PERF in target callbacks using existing scaling_min/max_freq
>>> interface similar to intel_cpufreq HWP handling, and exposes perf_limited
>>> register via sysfs to detect throttling events.
>>>
>>> The patches are grouped as below:
>>> - Patch 1: Add cppc_get_perf() API (independent).
>>> - Patch 2: Warn on missing mandatory DESIRED_PERF (independent).
>>> - Patch 3: Extend cppc_set_epp_perf for FFH/SystemMemory (independent).
>>> - Patch 4: Update cached perf_ctrls on sysfs write (independent).
>>> - Patch 5: Update MIN_PERF/MAX_PERF in target callbacks (depends on 4).
>>> - Patch 6-7: APIs, sysfs and doc for perf_limited (independent).
>> Gentle ping.
>>
>> If there are no further comments, could this be considered for merging.
> Applied as 7.1 material, thanks!

Thank you for applying the series.

>
> That said, wouldn't it be prudent to check cpc_read() return values 
> everywhere? They are handled quite inconsistently and this series 
> doesn't improve that. 

I will send a follow-up patch to address this.

Thank you
Sumit Gupta