Arch Linux

gcb

Member

Registered: 2014-02-12

Posts: 229

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

HDMI backlight would rather fall near ddcutil - did you maybe https://wiki.archlinux.org/title/KDE#Va … n_problems ?

The discussion was more about why things are changing with same versions.

Before updates: everything worked (both screens had brightness control)

After updated: everything broken

Rolling back both dccutil and amdgpu: no brigthness control at all.

The point was to figure out if something else might be the root cause of all this in the end, and the rollbacks of those packages just work around it.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 78,471

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

If you restored the *exact* status quote ante ( https://wiki.archlinux.org/title/Arch_L … cific_date ) one explanation could be that the bogus firmware altered an internal state of the HW.
Did the recent updates fix things for you as well?

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loqs

Member

Registered: 2014-03-06

Posts: 19,101

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

Was there a kernel update in the same timeframe as the linux-fimrware and ddcutil updates particularly was the system updated to 7.2 from 7.1.?

gcb

Member

Registered: 2014-02-12

Posts: 229

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

[deleted]

Last edited by gcb (2026-09-20 20:10:04)

gcb

Member

Registered: 2014-02-12

Posts: 229

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

no linux update at the same time. When the firmware packages changed, I was already on linux-7.2.4.arch1-2

It did include a bunch of other firmwares and a couple kde libs, so i will try to roll back those, who knows.
The fact it is now showing the bogus keyboard backlight brightness option might be hint it is NOT related to the amdgpu issue. (didn't have bogus option before)

(still have to take a couple hours to test the package rollback seth suggested to a certain date to rule out firmware settings damage

Last edited by gcb (2026-09-20 20:17:44)

gcb

Member

Registered: 2014-02-12

Posts: 229

Re: [SOLVED] Issues with linux-firmware-amdgpu 20260910-1

some closure on my brigthness slider missing!

Seems to have been a change on KDE. Now that yet another change landed, i see they were moving things around.

in the Settings > display window, you have an option "Brightness: [X] Control hardware brightness with DDC/CI"

Ironically, with this setting ON, I get no slider or control. With it off, i can then control my monitor with DDC via the applet slider go figure.