Arch Linux

patkoscsaba

Member

Registered: 2024-07-16

Posts: 23

No more external monitor brightness control after recent update

Hi everyone,

This is my system:

Operating System: Arch Linux 
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.1
Kernel Version: 6.12.1-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × Intel® Core™ i9-10885H CPU @ 2.40GHz
Memory: 31.0 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics
dGPU: Nvidia 1650
Manufacturer: LENOVO
Product Name: 20TKS0U300
System Version: ThinkPad X1 Extreme Gen 3

Up until a couple of days ago (Dec. 04, 2024) I was able to change the brightness of the external monitor connected to my laptop. Even more, if I set the internal and external displays to max, then they remained in sync and with the Fn+Brightness keys I could change the brightness of both external and internal screens simultaneously. I know this was a fairly new feature in KDE (this summer/autumn) and I really love it.

However, after I did my weekly update of Arch on Dec. 4, and it pulled in a bunch of new plasma and KDE packages, this feature disappeared.
I also noticed that the performance profile icon is not shown anymore either over the battery icon in the taskbar. I can still switch performance profiles clicking the battery icon and selecting one, but the handy icon showing the current profile is missing. I am not sure if this is related to the issue above, but I thought I mention it as well. This also changed after the same update.

Any ideas what to check or how to debug this? Is this a known issue? Did you see this happen to you or others?

---

Gigabyte Z890 Aorus Master Motherboard | Intel Core Ultra 9 285K | Corsair 128 GB RAM | Seagate 1TB M.2 | Seagate 2TB M.2 | Corsair 2TB M.2 | Intel Battlemage G21 [Arc B580]

dottmalcom

Member

Registered: 2024-11-27

Posts: 1

Re: No more external monitor brightness control after recent update

Same happened to me, on both, Lenovo laptop and desktop, but the strange thing is that i have 2 external monitors plugged in, the TV and a samsung monitor, both connected to S-Video to the GPU.
The TV still shows up, while the samsung is gone from the brightness widget menu.

zanetti

Member

From: Brazil

Registered: 2025-03-01

Posts: 1

Re: No more external monitor brightness control after recent update

I was struggling with this issue since last KDE Plasma update some days ago. Unfortunately, I haven't found any straightforward solution (it seems it's kind of new), only some advices about ddcutil or powerdevil on KDE forum.

I tryed reinstalling the packages above but nothing happened. Then, I just tried restarting the plasma-powerdevil and plasma-plasmashell user services and, again, nothing. These are the commands:

systemctl --user restart plasma-powerdevil.service
systemctl --user restart plasma-plasmashell.service

However, after rebooting the laptop, the brightness control slider for the HDMI monitor was there anyhow!

It's clear to me that this procedure solved the problem, but I'm unable to provide a decent explanation on what happened. I hope someone else can explain it and even find the reason behind the issue.

Good luck!