After many month of having this problem I finally found a solution that is working for me:
I changed /etc/default/grub, having now these two lines: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux" GRUB_CMDLINE_LINUX="quiet splash acpi_osi=Linux" Backlight is working fine with the hotkeys and in the control panel : ) Hope this helps someone! -- 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/ubuntu/+source/linux/+bug/954661/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
