This issue could be fixed by kernel after the below 2 patches are accepted. I think the second one is still in drm-intel-nightly git tree.
http://lists.freedesktop.org/archives/dri-devel/2013-September/045421.html http://www.spinics.net/lists/linux-acpi/msg47755.html -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1270079 Title: [Lenovo T540p, W540] Backlight interfaces not fully working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-raring/+bug/1270079/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
