Re: [PATCH 0/2] powercap: Introduce generic hierarchy helpers and selftests

[Manaf Meethalavalappu Pallikunhi <manaf.pallikunhi@oss.qualcomm.com>]

Hi Daniel,

On 9/7/2026 3:33 PM, Daniel Lezcano wrote:
> 
> Hi Rafael,
> 
> On 8/6/26 13:01, Daniel Lezcano wrote:
>> Powercap controllers frequently expose a hierarchy of power zones (for
>> example package, clusters and CPUs). Until now, each driver had to
>> implement its own hierarchy traversal, parent lookup, error handling and
>> teardown logic.
>>
>> This series introduces a generic hierarchy description and helper
>> functions allowing a controller to instantiate and destroy an entire
>> powercap hierarchy from a static description. The framework takes care of
>> duplicating the hierarchy description, rebasing parent pointers,
>> creating zones in dependency order and performing the appropriate
>> rollback and cleanup on errors.
>>
>> The series also adds a kselftest exercising the new API by creating a
>> synthetic hierarchy, validating the exported sysfs hierarchy and
>> attributes, and ensuring that all resources are correctly released when
>> the hierarchy is destroyed.
>>
>> The patches are organized as follows:
>>
>> 1. powercap: Add generic zone hierarchy creation helpers
>> 2. selftests/powercap: Add powercap hierarchy creation API tests
>>
>> The API was primarily motivated by the recently posted SPEL series and
>> also provides a migration path for DTPM to use the same generic
>> infrastructure instead of maintaining its own hierarchy handling.
>>
>> Link: SPEL cover letter <https://lore.kernel.org/lkml/20260702- 
>> qcom_spel_driver_upstream-v3-0-434d50f0c5b0@oss.qualcomm.com/>
>>
>> Daniel Lezcano (2):
>> powercap: Add generic zone hierarchy creation helpers
>> selftests/powercap: Add powercap hierarchy creation API tests
>>
>> -- 
> It was easy to migrate DTPM to this API and AFAICT Manaf was able to 
> migrate also its series to this new API.

Yes, I rebased my Qualcomm SPEL powercap driver series on top of this
patch and migrated the series without any issues.
These APIs significantly simplify the driver code for creating and
managing the powercap hierarchy.

Tested-by: Manaf Meethalavalappu Pallikunhi 
<manaf.pallikunhi@oss.qualcomm.com>

Thanks,
Manaf

> 
> Is it possible to consider it for merging ?
> 
> Thanks
> 
>    -- Daniel
> 
> [1] https://lore.kernel.org/all/20260819165605.1398880-1- 
> daniel.lezcano@oss.qualcomm.com/
> 
> [2] https://lore.kernel.org/all/20260702-qcom_spel_driver_upstream- 
> v3-0-434d50f0c5b0@oss.qualcomm.com/