Kernels >= 6.3 disable video output

[Steven J Abner]

On Mon, May 12 2025 at 08:10:40 PM +0000, Alex Deucher 
<alexdeucher at gmail.com> wrote:
> See:
> https://docs.kernel.org/admin-guide/bug-bisect.html
> ... identify the exact commit which broke caused your issue.

 One heck of a journey! But tested the solution on the first broken 
kernel 6.3. Too chicken to force revert attempts of 6.12 and 6.6 since 
I really didn't understand why revert spewed out 'nah-ah' for a one 
liner. 6.3 passed simple test of no blackouts for 8 in a row boots.
 Firstly let me qualify the revert, cause it's how i got it to work:
git show c76e483cd9163138e8fc44d829c986819f072d4f | patch --fuzz=999 
-p1 -R
 It seems simple enough of code which appears to set 8 bits of color 
for rgb as maximum, but with struct changes and me having a 
'historical' processor :) didn't want to have a non-expert speak that 
this is the full solution.
 Also note that I didn't 100% follow the bug-bisect guide as mine was 
apparently a unique situation where it had to first learn to connect to 
the internet and I don't use intrd images among other oddities. Also 
did this from last working kernel (6.2.16) to verify it was the last. 
PS had to patch amdgpu Makefile to allow the 6.2 series to compile with 
new gcc (-Wno-error).
 If need other info or need me to test actual patched 'upstream' 
kernel, I'm here.
Thank you!
Steve