Re: [PATCH 5/5] Documentation: add amd-pstate kernel command line options

Gautham R. Shenoy
2022-11-17T04:17:52Z

On Thu, Nov 17, 2022 at 10:49:55AM +0800, Perry Yuan wrote:
> Add a new amd pstate driver command line option to enable driver passive
> working mode via MSR and shared memory interface to request desired
> performance within abstract scale and the power management firmware
> (SMU) convert the perf requests into actual hardware pstates.
>
> Also the `disable` parameter can disable the pstate driver loading by
> adding `amd_pstate=disable` to kernel command line.
>
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

> ---
> Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a465d5242774..42af9ca0127e 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -6959,3 +6959,14 @@
> memory, and other data can't be written using
> xmon commands.
> off xmon is disabled.
> +
> + amd_pstate= [X86]
> + disable
> + Do not enable amd_pstate as the default
> + scaling driver for the supported processors
> + passive
> + Use amd_pstate as a scaling driver, driver requests a
> + desired performance on this abstract scale and the power
> + management firmware translates the requests into actual
> + hardware states (core frequency, data fabric and memory
> + clocks etc.)
> --
> 2.25.1
>