In finally managed to resolve the issue for my T430s. I had to add the following boot options to /etc/default/grub:
acpi_osi='!Windows 2012' - This makes the OSD work properly with 8 brightness steps video.brightness_switch_enabled=0 - This allows you to have 15 brightness steps (working OSD also included) The following comments seem to be related: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098216/comments/51 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098216/comments/54 Maybe it's still a regression? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1221795 Title: brightness stepping is incorrect (double what it should be) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1221795/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
