Re: [PATCH v8 0/7] Enhanced autonomous selection and improvements
From: Sumit Gupta
Date: Tue Mar 03 2026 - 12:33:10 EST
On 28/02/26 02:06, Rafael J. Wysocki wrote:
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On Thu, Feb 26, 2026 at 2:59 PM Sumit Gupta <sumitg@xxxxxxxxxx> wrote:
Applied as 7.1 material, thanks!
This patch series improves the CPPC cpufreq driver with new ACPI APIsGentle ping.
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).
If there are no further comments, could this be considered for merging.
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