It seems the _BCM is broken (_BCM is called when writing to /sys/class/backlight/acpi_video0/brightness).
We will need BIOS to fix it (if it is still possible). ** Changed in: linux-lts-raring (Ubuntu) Status: In Progress => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1255014 Title: [Lenovo V480] Unable to control the brightness from Max - Min To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-raring/+bug/1255014/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs