This can be fixed by adding `acpi_backlight=vendor` to the `linux` stanza in `grub.cfg` which is effectively done by adding it to `GRUB_CMDLINE_LINUX_DEFAULT` in `/etc/default/grub` in Ubuntu 17.10 or possibly earlier.
I'm leaving this open in order to suggest improvement of automatic handling of this issue. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1465266 Title: [xorg-edgers] lowering brightness with hotkeys causes it to drop to the minimum and stay minimal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1465266/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp