14 DAY TRIAL // We reported a while ago that the Brightness setting in Ubuntu 13.10 was not wroking properly, especially for Intel systems. It seems that the problem has been inherited in Ubuntu 14.04 (Trusty Tahr).
If you happen to have an Intel-based system, with an Intel graphics solution, you might have experienced a minor problem with the brightness setting.
In short, users are unable to change the brightness of the display. The slider found in “Settings”, under “Brightness & Lock” doesn't do anything. Even worse, if you have a laptop that's charging, the brightness setting is set to low when the charging process has been completed. Users need to removed the charger and plug it again to restore the brightness setting.
Lauchpad is full of entries for this problem and it doesn't seem to be limited to Intel problem. This is just one of the examples.
NVIDIA also had some problems with this problem, but it's not affecting the entire Ubuntu user base. Given the fact that Ubuntu 14.04 (Trusty Tahr) is also affected by the problem, it's very likely that this is an upstream issue. This shouldn't stop Ubuntu developers from integrating a fix in the next release, which is set to be an LTS version.
Fortunately, I discovered a workaround for Intel integrated solutions and it's quite simple. Enter the following command in a terminal (you will need the root password to make this work).
sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf
This will open a text file, with root access. Enter the following text and save the document. Logout and log back in to fix the problem. Section "Device" Identifier "card0" Driver "intel" Option "Backlight" "intel_backlight" BusID "PCI:0:2:0"
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The brightness settings should work again. If you encountered this problem on other configurations, please leave a comment below. Also, if you know of any other solutions that are simpler that the one mentioned above, don't be shy and let everyone know.