Re: [PATCH 9/9] Documentation/amd-pstate: Add documentation for amd_pstate_floor_{freq,count}

[K Prateek Nayak <kprateek.nayak@amd.com>]

Hello Gautham,

On 3/6/2026 3:27 PM, Gautham R. Shenoy wrote:
> +``amd_pstate_floor_freq``
> +
> +The floor frequency associated with each CPU. Userspace can write any
> +value between ``cpuinfo_min_freq`` and ``scaling_max_freq`` into this
> +file. When the system is under power or thermal constraints, the
> +platform firmware will attempt to throttle the CPU frequency to the
> +value specified in ``amd_pstate_floor_freq`` before throttling it
> +further. This allows userspace to specify different floor frequencies
> +to different CPUs. For optimal results, threads of the same core
> +should have the same floor frequency value. This file is only visible
> +on platforms that support the CPPC Performance Priority feature.

nit. Should we note that the driver caches the closes perf value and the
read of the file will output the corresponding frequency of the perf
level?

Otherwise, it might come as a surprise to the user that the read of file
returns a value very close to what was written but not exactly equal to
it all the times.

Or should we just cache the raw frequency value when user modifies it
and keep the perf translation bits opaque to the user?

-- 
Thanks and Regards,
Prateek