Brightness controls don't work on Macbook - Stuck on high (Nvidia GeForce 9400M)

I am using a Macbook (Aluminum Late 2008 version) and dual booting ubuntu 12.10

After installation the keyboard controls for volume and brightness worked perfectly,but a few days later the brightness got stuck on high and it's been giving me headaches and is super annoying. I can't use the keyboard controls for brightness or change it in the settings. I've tried searching for a fix but nothing has worked so far. Any suggestions?

Also i have played around with the graphics drivers and i'm currently using: NVIDIA binary Xorg driver. Should i change this? (Go easy on me, i'm a newbie :))

Graphics: Nvidia GeForce 9400M/integrated/SSE2 OS Type: 32-bit I'll provide any extra information needed

1 Answer

♡ I found a solution! Hopefully someone finds this useful. I probably did more steps than required but here is what worked for me. ♡ (Nvidia users only)

1. Open Terminal and enter the command below to open the xorg.conf file for editing:

   sudo -H gedit /etc/X11/xorg.conf

2. Once the file opens, find Section “Device” and add

   Option "RegistryDwords" "EnableBrightnessControl=1" 

   (as shown below in bold line), and hit CtrlS to save it.

In my case, this file was empty so I entered the exact text and saved it to /etc/X11.

Section "Device"
Identifier "Default Device"
Option "NoLogo" "True"
Option "RegistryDwords" "EnableBrightnessControl=1″
EndSection

Source

After restarting, if this did not work for you I also did the following:

3. Just create a file in /etc/X11/xorg.conf.d/50-nvidia.conf with the following content:

   Section "Device" Option "RegistryDwords" "EnableBrightnessControl=1" Identifier "Device0"
   EndSection

   Again, in my case some of these files didn't exist so I created them myself. When everything was in place I restarted and now my brightness controls are working

In order to create them manually open terminal and enter:

gksu nautilus

From there on navigate to: /etc/X11/ and create a folder named xorg.conf.d. Then inside that folder create a file named 50-nvidia.conf using gedit with the content listed in the step 3.

Now restart your computer.

Source