Macbook Pro 8,2 and 8,3 notebooks with ATI Radeon graphics have an unusual kind of backlight that requires the "gmux" driver. I don't really understand all the details. However, I found a substitute "apple_bl" and "apple_gmux" driver for Ubuntu. Downloaded deb packages from Ubuntu maintainer: http://ppa.launchpad.net/sforshee/apple-bl-gmux/ubuntu/pool/main/a/ Explanation here: https://wiki.ubuntu.com/Kernel/AppleGmuxBacklight I used alien to convert the deb to rpm and installed it. It's a dkms package but it didn't work in Mageia. However, I was able to fix the Makefile (in the included attachment) and just compile it with "make" and it works and allows me now to control the Apple backlight on these computers. I don't know if substituting THIS apple_bl driver will break the standard apple_bl driver that comes with the 3.3.3 kernel. I compiled both the apple_bl and apple_gmux drivers and put them in /lib/modules/3.3.3.../extra and, after removing /lib/modules/3.3.3.../kernel/drivers/video/backlight/apple_bl.ko.. I ran depmod -a and this driver works. When I run: modprobe apple_bl modprobe apple_gmux I get a new listing at /sys/class/backlight/gmux_backlight/brightness I'm not suggesting putting this in Mageia 2. You probably have too much to worry about right now. But you might want to do something with this in the future.
Created attachment 2079 [details] Apple gmux backlight drivers
Created attachment 2080 [details] A script to raise and lower the backlight values This script was originally written for ubuntu, to be used with the standard apple backlight (apple_bl) which has values of 0-15. The gmux driver seems to take values from 0 - 110000, so you need much bigger increments.
Maybe you can attach
Assignee: bugsquad => tmb
Created attachment 2093 [details] Alternate apple_bl.c file
Created attachment 2094 [details] Makefile for apple_bl.c
Created attachment 2095 [details] apple_gmux.c
Created attachment 2096 [details] Makefile for apple_gmux.c
Not sure what you wanted me to attach. I had previous attached the driver source files in a single zip file, but here they are individually.
Created attachment 2097 [details] A script to raise and lower the backlight values I am re-attaching the script to raise/lower the backlight values. I have adpated it from the original script to reference the new location of the backlight sys file.
Attachment 2080 is obsolete: 0 => 1
arf sorry it was for the dmesg, but it seems not necessarily
Hi, This bug was filed against cauldron, but we do not have cauldron at the moment. Please report whether this bug is still valid for Mageia 2. Thanks :) Cheers, marja
Keywords: (none) => NEEDINFO
I think you should close this bug, but only after reading the following: This is NO LONGER A PROBLEM for Mageia 2. I am not sure how Mageia solved the problem but I installed Mageia 2 on the Macbook 8,2 laptop and the backlight is working. I see that the Mageia 3.3.6 kernel does NOT have the apple_gmux module, but for some reason the apple_bl module must just be working. I confirmed that if I go to cd /sys/class/backlight/apple_backlight/ and run echo 10 > brightness or echo 15 > brightness I am able to bring the brightness up and down. This did NOT work in beta versions of Mageia 2. Note that in Kubuntu 12.04, they have patched in the apple_gmux driver into their kernel and adjusting /sys/class/backlight/apple_backlight/brightness has NO EFFECT on Kubuntu. On Kubuntu, you need to adjust the value for the gmux_backlight So, this is a bit confusing, but somehow it's working in Mageia. I'm not saying the Kubuntu approach is the right one. Perhaps support for the new backlight was properly patched into the 3.3 kernel, whereas Kubuntu 12.04 is still using the 3.2 kernel?
Version: Cauldron => 2
So i'm closing it as worksforme, feel free to reopen if needed.
Keywords: NEEDINFO => (none)Status: NEW => RESOLVEDCC: (none) => sander.lepikResolution: (none) => WORKSFORME