Re: [PATCH v4 0/2] cpufreq: CPPC: add autonomous mode boot parameter support

[Sumit Gupta <sumitg@nvidia.com>]

On 28/05/26 01:55, Sumit Gupta wrote:
> This series adds a kernel boot parameter 'cppc_cpufreq.auto_sel_mode'
> to enable CPPC autonomous performance selection on all CPUs at system
> startup, avoiding per-CPU sysfs scripting at every boot.
>
> When autonomous mode is enabled, the hardware automatically adjusts
> CPU performance based on workload demands using Energy Performance
> Preference (EPP) hints.
>
> Patch 1: Sets CPPC Enable Register for both OS-driven and autonomous
> CPPC control modes. It can be applied independently of patch 2.
>
> Patch 2: Adds the auto_sel_mode boot parameter with three modes:
>    - performance (or 1):         override EPP to performance (0x0)
>    - balance_performance (or 2): override EPP to balance_performance (0x80)
>    - default_epp (or 3):         preserve EPP value programmed by
>                                  BIOS/firmware
>
> Patch 2 depends on Pierre's series [4] ("cpufreq: Set policy->min and
> max as real QoS constraints") so that policy->min/max set during
> cppc_cpufreq_cpu_init() are not overridden by cpufreq_set_policy().
>
> v3[3] -> v4:
> - Add 'balance_performance' mode which sets EPP to 0x80.
> - Add CPPC_EPP_BALANCE_PERFORMANCE_PREF (0x80) constant in cppc_acpi.h.
> - Clean up EPP mode selection with switch + boolean flag in cpu_init.
> - Use local variable for kp->arg in auto_sel_mode_set/get to avoid
>    repeated casts.
>
> Sumit Gupta (2):
>    cpufreq: CPPC: Set CPPC Enable register in cpu_init
>    cpufreq: CPPC: add autonomous mode boot parameter support
>
>   .../admin-guide/kernel-parameters.txt         |  20 +++
>   drivers/cpufreq/cppc_cpufreq.c                | 154 +++++++++++++++++-
>   include/acpi/cppc_acpi.h                      |   1 +
>   3 files changed, 170 insertions(+), 5 deletions(-)
>
> [1] v1: https://lore.kernel.org/lkml/20260317151053.2361475-1-sumitg@nvidia.com/
> [2] v2: https://lore.kernel.org/lkml/20260424201814.230071-1-sumitg@nvidia.com/
> [3] v3: https://lore.kernel.org/lkml/20260515122624.1920637-1-sumitg@nvidia.com/
> [4] https://lore.kernel.org/lkml/20260511135538.522653-1-pierre.gondois@arm.com/
>

Gentle ping on this series.

The dependency it was waiting on, the "cpufreq: Set policy->min and
max as real QoS constraints" series, is now in linux-pm (linux-next).
I rebased on top and verified autonomous mode works as expected, and
it applies cleanly on the current linux-next.

The [1] reference in patch 2/2 points to v2 of that series; the merged
version is v3 [2].

If there are no further comments, please consider acking and queuing
this for the next cycle.

Thanks for your time.

[1] 
https://lore.kernel.org/lkml/20260511135538.522653-1-pierre.gondois@arm.com/
[2] 
https://lore.kernel.org/lkml/20260528090913.2759118-1-pierre.gondois@arm.com/

Regards,
Sumit