Yes kaihengfeng. Now, my GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=Linux acpi_backlight=vendor" and /sys/class/backlight still empty. Today I've updated the laptop and the kernel is 4.13.0-38-generic and the problem still happening.
I hope in this week, I can change my kernel to test this solution. Thanks kaihengfeng. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1758496 Title: Backlight does not work on a MacBookAir3,2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1758496/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
