Arch Linux

linuxbro

Member

Registered: 2017-04-10

Posts: 11

[SOLVED] Backlight Control broken after upgrade - KDE Plasma 5.12.5

Greetings.
A recent upgrade in April broke my backlight control. I have been searching this forum and on web but have found no solution.

- keyboard brightness buttons activate GUI but do not change brightness
- Plasma Gui slider does not change brightness

- /sys/class/backlight/acpi_video0 and /etc/X11/xorg.conf were removed. I had previously configured xorg.conf to use acpi_video0 successfully per the directions in the "Backlight" section of the Arch Wiki.

- "xbacklight -set xx" executes, but does not effect display
- "xrandr --output LVDS1 --brightness 2" works, however will not brighten the screen if the system boots with the screen dimmed.
- redshift works
-
Hardware:
SAMSUNG  NP510R5E-A02UB Laptop
Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
CPU: Intel Core i7-3537U @ 4x 2.00GHz
RAM: 7866MiB
System:
Kernel: x86_64 Linux 4.14.38-1-lts
KDE 5.45.0 / Plasma 5.12.5
updated today, rebooted

Was there a system update effecting backlight that I missed?
Thanks.

Last edited by linuxbro (2018-05-03 06:03:12)

linuxbro

Member

Registered: 2017-04-10

Posts: 11

Re: [SOLVED] Backlight Control broken after upgrade - KDE Plasma 5.12.5

I downgraded to 4.14.24-1-lts per
https://bbs.archlinux.org/viewtopic.php?id=236473

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,620

Re: [SOLVED] Backlight Control broken after upgrade - KDE Plasma 5.12.5

Read the thread you linked to to the end, there's a much more sustainable solution that doesn't involve downgrading.

linuxbro

Member

Registered: 2017-04-10

Posts: 11

Re: [SOLVED] Backlight Control broken after upgrade - KDE Plasma 5.12.5

Right! Thanks for the follow up. Happily working now.