Adding GRUB_CMDLINE_LINUX="nomodeset acpi_backlight=vendor" in /etc/default/grub and running update-grub works as a workaround for me too.
-- Screen brightness does not function on Acer Aspire Timeline 5810TZ https://bugs.launchpad.net/bugs/438537 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-power-manager in ubuntu. -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
