Re: [PATCH v11 09/11] Documentation: introduce amd pstate active mode kernel command line options

From: Wyes Karny
Date: Thu Jan 19 2023 - 00:33:20 EST




On 1/18/2023 1:22 PM, Perry Yuan wrote:
> AMD Pstate driver support another firmware based autonomous mode
> with "amd_pstate=active" added to the kernel command line.
> In autonomous mode SMU firmware decides frequencies at runtime
> based on workload utilization, usage in other IPs, infrastructure
> limits such as power, thermals and so on.
>
> Acked-by: Huang Rui <ray.huang@xxxxxxx>
> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Tested-by: Wyes Karny <wyes.karny@xxxxxxx>
> Signed-off-by: Perry Yuan <perry.yuan@xxxxxxx>
Reviewed-by: Wyes Karny <wyes.karny@xxxxxxx>

> ---
> Documentation/admin-guide/kernel-parameters.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6cfa6e3996cf..e3618dfdb36a 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -7020,3 +7020,10 @@
> management firmware translates the requests into actual
> hardware states (core frequency, data fabric and memory
> clocks etc.)
> + active
> + Use amd_pstate_epp driver instance as the scaling driver,
> + driver provides a hint to the hardware if software wants
> + to bias toward performance (0x0) or energy efficiency (0xff)
> + to the CPPC firmware. then CPPC power algorithm will
> + calculate the runtime workload and adjust the realtime cores
> + frequency.

--
Thanks & Regards,
Wyes