Macbook 2,1 panel brightness no longer adjustable in Karmic/Lucid

[Kevin]

Problem occurs with: Ubuntu 9.10, Ubuntu Lucid
Does not occur with: Ubuntu 9.04 and earlier

My Macbook's brightness keys have always worked in previous versions of Ubuntu, but as of Karmic, it appears it no longer detects a backlight device. There is no laptop_panel device in lshal, and the screen brightness panel applet reports "Cannot get laptop panel brightness".

ProblemType: Bug
Architecture: amd64
Date: Wed Oct 21 22:24:52 2009
DistroRelease: Ubuntu 9.10
Package: devicekit-power 011-1ubuntu1
ProcEnviron:
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: devicekit-power
Uname: Linux 2.6.31-14-generic x86_64

[Richard (richarderiley)]

I'm having the same problem on the Samsung NC10.

[Victor Ashik (vashik+)]

I'm having the same problem on MacBook 2,1 in Lucid and Karmic.

[Colin D Bennett (colinb)]

I have a MacBook 5,1 and my backlight brightness stopped working several months ago. It worked at one point with Karmic, but after some automatic package update it quit working. I'm still on Karmic and it's still broken.

I press the Fn backlight brighter/darker keys and the OSD indicator by the Gnome system tray pops up and its brightness bar indicator changes, but the actual screen brightness does not change. I try to write the brightness manually by writing to the appropriate /sys/class/backlight/... file, but it doesn't have any visual effect:

cdb@svelte:~$ echo 10 | sudo tee /sys/class/backlight/nvidia_backlight/brightness
10
cdb@svelte:~$ echo 255 | sudo tee /sys/class/backlight/nvidia_backlight/brightness
255
tee: /sys/class/backlight/nvidia_backlight/brightness: Invalid argument
cdb@svelte:~$ echo 55 | sudo tee /sys/class/backlight/nvidia_backlight/brightness
55
tee: /sys/class/backlight/nvidia_backlight/brightness: Invalid argument
cdb@svelte:~$ echo 1 | sudo tee /sys/class/backlight/nvidia_backlight/brightness
1

It's really frustrating since it worked earlier with Karmic and then suddenly broke!

[Rainer Rohde (rainer-rohde)]

Same on my MBP 5,2 17"... very frustrating indeed!

[Matthew Paul Thomas (mpt)]

For me the brightness keys now work, adjusting the brightness and producing notification bubbles. The brightness panel applet still reports "Cannot get laptop panel brightness", though.

[Yosha872 (yosha)]

Note : it's working on Xubuntu 18.04 (and Lubuntu 18.04) on a Macbook 2,1 (2007, CPU Intel Core 2 duo T7400) : panel brightness adjustable with FN keys. Linux kernel : 4.15.0-20