[REGRESSION] amd-pstate doesn't work since v5.18.11

Oleksandr Natalenko
2022-07-12T17:40:40Z

Hello Mario.

The following commits were pulled into v5.18.11:

```
$ git log --oneline --no-merges v5.18.10..v5.18.11 | grep ACPI
2783414e6ef7 ACPI: CPPC: Don't require _OSC if X86_FEATURE_CPPC is supported
3068cfeca3b5 ACPI: CPPC: Only probe for _CPC if CPPC v2 is acked
8beb71759cc8 ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported
13bb696dd2f3 ACPI: CPPC: Check _OSC for flexible address space
```

and now this happens:

```
$ sudo modprobe amd-pstate shared_mem=1
modprobe: ERROR: could not insert 'amd_pstate': No such device
```

With v5.18.10 this worked just fine.

In your upstream commit 8b356e536e69f3a4d6778ae9f0858a1beadabb1f you write:

```
If there is additional breakage on the shared memory designs also
missing this _OSC, additional follow up changes may be needed.
```

So the question is what else should be pulled into the stable tree to unbreak amd-pstate?

Thanks.

--
Oleksandr Natalenko (post-factum)