Re: [PATCH 00/12] Recover sysfb after DRM probe failure

Mario Limonciello
2026-01-16T14:03:08Z

On 1/15/26 10:36 AM, Gerd Hoffmann wrote:
> Hi,
>
>>> At least for AMD GPUs remove_conflicting_devices() really early is
>>> necessary because otherwise some operations just result in a
>>> spontaneous system reboot.
>
>> It's similar for Intel. For us VGA emulation won't be used for EFI
>> boot, but we still can't have the previous driver poking around in
>> memory while the real driver is initializing. The entire memory layout
>> may get completely shuffled so there's no telling where such memory
>> accesses would land.
>
> Can you do stuff like checking which firmware is needed and whenever
> that can be loaded from the filesystem before calling
> remove_conflicting_devices() ?
>

That's something that I did in amdgpu a few years back.

I pushed the identification and ability to load firmware into early init
stages. It means that if you have a brand new GPU and run a modern
kernel with an older linux-firmware snapshot amdgpu will fail probe and
your framebuffer from EFI keeps working.