I've a X220 with 14.04 and I'm facing the above problem aswell. In my setup I do have a docking station with an external monitor hooked up. Undocking my notebook darkens the notebook screen. Docking it again gives normal brightness and "undocking" again gives again regular brightness. So the problem occuse only the first time of undocking.
A solution would be great. With regular and unchanged 14.04 installation and kernel version "Linux mybook 3.13.0-36-generic #63-Ubuntu SMP Wed Sep 3 21:30:07 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux" -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1308674 Title: [Lenovo ThinkPad X220] kernel 3.13 i915 brightness settings broken when going from docked -> undocked To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1308674/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
