RE: amd-pmc s2idle driver issues

[Alexander Monakov]

On Tue, 22 Dec 2020, Deucher, Alexander wrote:

> > Yes. Out-of-the-box it's a "modern standby" laptop. There's a "hidden"
> > bios menu with extra settings that apparently allows to select legacy S3.
> > I did not change it, so I'm testing the "modern" mode.
> > 
> > Note that this driver fetches SMU version from MMIO, which looks odd to
> > me:
> > elsewhere (i.e. in the amdgpu driver) SMU version is retrieved by issuing the
> > corresponding SMU command, as far as I can tell.
> 
> There are multiple interfaces to the SMU. It's shared by the entire SoC on
> APUs.

Just pointing that out because evidently this interface does not work on this
laptop, producing all-ones instead of something resembling a version number.

Which APU generations does this driver support? If it does not support Renoir
(yet?) it should be documented in the Kconfig text. Is Renoir support related
to missing AMD0005 ACPI id binding, and borked version number info?

Alexander