kern/57325: Crash on boot w/ amdgpu driver on Lenovo ThinkCentre M75n

[germain%lanvaux.ca@localhost]

>Number:         57325
>Category:       kern
>Synopsis:       Crash on boot w/ amdgpu driver on Lenovo ThinkCentre M75n
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 06 02:25:00 +0000 2023
>Originator:     Germain Le Chapelain
>Release:        Current (10.99.2)
>Organization:
Lanvaux Computer Games Limited
>Environment:
NetBSD germ2.lanvaux.fr 10.99.2 NetBSD 10.99.2 (GENERIC) #0: Mon Apr  3 01:29:03 PDT 2023  german%germ2.lanvaux.fr@localhost:/usr/src/sys/arch/amd64/compile/obj/GENERIC amd64

>Description:
It crashes on boot with a call stack after some error in dmesg, notably `unable to locate a BIOS ROM'.

I'm still not 100% on debugging kernel, so I have an actual screenshot here:

http://lanvaux.fr/.download/projs/support/IMG_5866.JPG
>How-To-Repeat:
Compile the current source w/ amdgpu & amdgpufb lines uncommented in `GENERIC' and install & run on a Lenovo ThinkCentre M75n
>Fix:
I'm sorry I want to help more.
I can keep looking down the code though rly not sure how far I can take it.

Up, it *looked* like some function was returning IERRVAL (-1?) and some function was checking that against 0 to determine if there was a problem.

But that's after the problem of `nor being able to locate the BIOS'.