[RFC PATCH] drm/amd/pm: add zero RPM OD setting support for SMU13

[Wolfgang Müller]

On 2024-10-19 16:37, Wolfgang Müller wrote:
> Whilst we have support for setting fan curves there is no support for
> disabling the zero RPM feature. Since the relevant bits are already
> present in the OverDriveTable, hook them up to a sysctl setting so users
> can influence this behaviour.
> 
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3489
> Signed-off-by: Wolfgang Müller <wolf at oriole.systems>
> ---
> I've been wanting this feature for a while so today I sat down and had a
> look at how to best implement it. This is my first ever look at amdgpu
> code, so I've marked it with RFC. I've based it on the implementation of
> eedd5a343d22 (drm/amd/pm: add fan target temperature OD setting support
> for SMU13, 2023-08-11) and also hooked resetting the knob with "r".
> 
> One thing I'm unsure about is using PP_OD_FEATURE_ZERO_FAN_BIT for
> FeatureCtrlMask. I'm not sure this is the right thing to use there.
> 
> I successfully tested this on my own system with a 7900XTX; enabling and
> disabling as well as resetting the knob to its default value work fine.

I'd love to see this feature in the driver, so would very much welcome
some feedback on this topic.

Thanks!

-- 
Wolf