Ubuntu
linux package

  1. Bug #1983180
  2. Comment #67

Comment 67 for bug 1983180

Revision history for this message
In , manuel.lauss (manuel.lauss-linux-kernel-bugs) wrote :

(In reply to Manuel Lauss from comment #63)
> This patch also disables CPPC support on a few of my relatively recent AMD
> Zen Desktop systems. The issue is that the ACPI _OSC method supports ONLY
> the UUID of the "PCI root bridge device", but not any other, but linux is
> looking for CPPC support with the "Platform-Wide OSPM Capabilities" uuid,
> which does not
> exist anywhere in the firmware. bios engineers told me that this is all
> part of AMDs AGESA thingie, and they won't be able to add support for this,
> at least
> on current (i.e. zen3-supporting) platforms.
>
> Could this be worked around, by first checking whether any _CPC objects
> exist, and maybe a matching PCC entry?

Oh I see this was fixed recently with
fbd74d16 ("ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory").