Re: [PATCH] drm/amd/amdgpu: add firmware file fallback for APU VBIOS discovery

[Arnaud BERTRAND]

> On Mon. Nov  2. 2026 at 14:58, Alex Deucher <alexdeucher@xxxxxxxxx> wrote :
>
> >On Mon, Nov 2, 2026 at 3:07 AM Arnaud BERTRAND <arnaud078@xxxxxxxxx> wrote:
> >
> > Hello,
> >
> > I have two dGPUs : a Radeon RX 6800
> > XT and a Radeon RX 6800. They both report the same PCI identity
> > 1002:73bf and each has a different VBIOS.
> > I hit the same VFCT bus-number mismatch on 7.2.10, but with a different
> > outcome: on my machine the device-identity fallback actively breaks the second
> > dGPU.
> > I patched my kernel to remove the fallback, but I would like to have a
> > better solution for my use case.
> > Would it be possible to apply the patch only to APUs ? That would keep
> > Oz's APU case working but a dGPU with a stale bus number would fall
> > through to its own ROM, which is the source that is
> > guaranteed to match the card in the slot.
> > I can provide more details if needed, I am out of my depth here.
>
> Should be fixed with this patch series:
> https://patchwork.freedesktop.org/series/176969/
This patch series applied on top of kernel 7.3.0 indeed fixed the
issue for me. Thanks Alex and Mario for the swift answers.
>
> Alex
>
> > Thanks
> > Arnaud