If you are using the XPS 13 L322x HD syste and booting with the EFI loader you may want to try setting your bios to these settings.
I booted into my XPS bios setup, navigated to the boot tab, and configure the setting as below; Secure Boot: Disable Load Legacy Option Rom: Enabled Boot List Option: UEFI -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/954661 Title: backlight brightness not adjustable by default on Dell XPS 13 To manage notifications about this bug go to: https://bugs.launchpad.net/dell-sputnik/+bug/954661/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
