Re: [REGRESSION] Please revert 1191285ecb42 from 7.1.y

[Sergio Callegari <sergio.callegari@gmail.com>]

On 11/08/2026 07:24, Thorsten Leemhuis wrote:
 >
 > And yes, 6.18.y seems affected, too, according to a comment in the
 > ticket linked below.
 >

Yes, my bad I only mentioned 7.1.6 to be quick. My actual concern is 
that the troublesome commit got to the LTS kernels, which I think is the 
biggest issue right now. People may find their display completely black 
or almost black as soon as their DE starts. Getting to the conclusion 
that they need to /reduce/ the brightness to recover is not totally 
obvious and is not applicable at all if you have a system that is 
touchscreen only (since you won't be able to see where to press).

 >> It needs to be reverted in Linus's tree first, otherwise the regression
 >> will be hit when you update to 7.2.

Indeed, but I think the biggest issue is with the LTS kernels right now.

 > Normally I'd agree, but according to one reporter that problem does not
 > happen with 7.2-rc:
 > https://gitlab.freedesktop.org/drm/amd/-/work_items/5562#note_3603131

I'll see if I can try myself the 7.2 RCn series. From my superficial 
analysis of the commits that brought us to the current situation, the 
troublesome commit actually tried to patch on a true issue, namely that 
the user facing brightness data is not mapped symmetrically to the 
hardware data, but that the correct solution involves some more thorough 
rework of the brightness coordinate system. So there may well be some 
larger activity on it on upstream.
 >
 > Given all that I wonder if dropping that commit for now might be the
 > best move.

Personally, I think that dropping on the stable series would be 
beneficial, unless upstream can now offer a correct solution to pick. 
Behavior you get by dropping is not 100% ideal but certainly not as bad 
as what you get with the problematic commit.

Best,
Sergio