Re: [PATCH v2] PCI: release empty sibling bridge windows during rebar expansion

Mario Limonciello
2026-04-11T17:42:38Z

On 4/11/26 11:30, Geramy Loveless wrote:
> Mario,
>
> Yeah I would consider this a bios bug but it seems the MS-S1 isn’t the
> only one with it. I’m not sure how bios development goes together or
> who standardizes the ACPI table that would be the right way to fix
> this.

BIOS development is generally done by independent BIOS vendors (IBVs).
These vendors work with OEM and ODM for BIOS solutions. It's entirely
possible the same problem happens on multiple systems, but it doesn't
change the fact it's a BIOS issue.

>
> I would think the faster way is to adapt the AMD driver to use the
> Thunderbolt provided function in the kernel to detect if it’s on a hot
> plug table port.
> Which would only work on driver versions that where> introduced
during the time the kernel had that new capability. It
> could get backported / patched. That in my eyes would be the fastest
> resolution, correct or not.

We shouldn't choose a solution based upon how quickly it can be merged.

But in terms of a solution to this BIOS issue, what is wrong with adding
that it's thunderbolt connected "to the cases" that it was detected as
removable?

Then it can be applied to all drivers that use a removable check; not
just amdgpu.

> We could update the ACPI table during
> kernel load but that seems a lot more hacky then using pre-existing
> thunderbolt provided functionality for detecting if the device is on
> Thunderbolt.

Right - we shouldn't look at ACPI table modification for a kernel
solution. You can try this locally to prove that things work properly
with what appears as a correct BIOS though.

>
> I already patched the driver with the additional thunderbolt function
> call, I’m not seeing any problems at all. My kernel loaded with the
> devices connected and made it the primary display PITA but Linux has
> always been a PITA for displays haha. :) once done what is your
> recommendations for submitting all 8 patches I believe or should I
> just do one for adding “is thunderbolt” function call?
>
> Sorry about the last reply my phone doesnt like text only mode.
>
> Thanks!

I'd say try adding it as one of the cases to removable detection and see
how well that works.