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Av32000

Member

Registered: 2025-07-24

Posts: 2

[Solved] Bug with amdgpu_bl1 : 0% brightness is brighter than 1%.

Hi! I recently discovered a weird behavior with my brightness driver (amdgpu_bl1). When I decrease the brightness from 100% to 1%, it behaves normally. But when I go from 1% to 0%, my screen actually becomes brighter than at 1%.

I tested this with brightnessctl and observed the following behavior:

~> brightnessctl
Device 'amdgpu_bl1' of class 'backlight':
Current brightness: 1110 (2%)
Max brightness: 61680

<press the brightness down key on my keyboard>
<physical screen brightness goes down>

~> brightnessctl
Device 'amdgpu_bl1' of class 'backlight':
Current brightness: 617 (1%)
Max brightness: 61680

<press the brightness down key again>
<physical screen brightness goes down>

~> brightnessctl
Device 'amdgpu_bl1' of class 'backlight':
Current brightness: 310 (1%)
Max brightness: 61680

<press the brightness down key again>
<physical screen brightness goes down — but I'm still at 1% (first weird behavior)>

~> brightnessctl
Device 'amdgpu_bl1' of class 'backlight':
Current brightness: 135 (0%)
Max brightness: 61680

<physical screen brightness goes UP ???>

By manually setting brightness values using "brightnessctl set <value>", I noticed the following:

    Any value between 310 and 187 results in the same brightness level.

    Any value below 187 causes the physical brightness to jump up to a level close to 3701 (around 6%).

Can someone explain this behavior or help me troubleshoot the issue?

Last edited by Av32000 (2025-07-24 23:53:10)

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 70,997

Re: [Solved] Bug with amdgpu_bl1 : 0% brightness is brighter than 1%.

https://bbs.archlinux.org/viewtopic.php … 4#p2248154 ?

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Av32000

Member

Registered: 2025-07-24

Posts: 2

Re: [Solved] Bug with amdgpu_bl1 : 0% brightness is brighter than 1%.

Fixed Thanks !