Please reopen. This happens to me for Ubuntu 14.04 on a Lenovo T530 with nvidia drivers. It only happens when I switch to Discrete Graphics in the BIOS, but running in Optimus breaks other things (cannot change the virtual layout of external screens without glitches).
Using all the proposed kernel parameters in this thread so far as well as adding the EnableBrightnessControl line only prevents freezing the system, but the brightness does not change. I also tried xbacklight and changing the value in /sys/class/brightness/.../brightness. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/776999 Title: [Lenovo W520] laptop freezes on ACPI-related actions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/776999/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
