Unable to boot 5.18-rc kernel on amdgpu legacy (si) hardware.

[Alex Deucher]

On Fri, Apr 15, 2022 at 12:00 PM Paul Blazejowski
<paulb at blazebox.homeip.net> wrote:
>
> Hello,
>
> I am unable to boot 5.18-rc1(2) kernel with my rather old (si) XFX card,
> which works fine under 5.17.3 and previous kernels.
>
> The card is identified as:
>
> 1:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI]
> Cape Verde PRO [Radeon HD 7750/8740 / R7 250E]
>
> Running on a Asus M5A99FX PRO R2.0 mainboard.
>
> The boot process stops at "fb0: EFI VGA frame buffer device" step and
> the hdmi connected monitor just shuts off, there's not oops or any other
> debug output captured by serial console.
>
> I was able to bisect the kernel tracing this to a bad commit:
>
> git bisect bad 3712e7a494596b26861f4dc9b81676d1d0272eaf
> # first bad commit: [3712e7a494596b26861f4dc9b81676d1d0272eaf]
> drm/amd/pm: unified lock protections in amdgpu_dpm.c
>
> And reverting this commit on 5.18-rc2 kernel makes my system bootable again.
>
> Please let me know if there's anything else i could provide to help fix
> this issue. I have access to serial console if needed.

Fixed with this patch:
https://patchwork.freedesktop.org/patch/481477/

Alex

>
> Thank you.