Ubuntu
gnome-settings-daemon package

  1. Bug #915188
  2. Comment #52

Comment 52 for bug 915188

Revision history for this message
Guillaume Michaud (gfmichaud) wrote :

This has to do with ACPI.
I solved this problem on my Asus Zenbook UX31E (with latest BIOS) this way :

1) I added acpi_osi='!Windows 2012' acpi_backlight=vendor in /etc/default/default so that the line looks like
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi='!Windows 2012' acpi_backlight=vendor"

2) I ran sudo update-grub (to re-generate GRUB conf files)

To explain, I forced the kernel to say to the BIOS that Windows 8 is running on the laptop.
Maybe something similar should work on other PCs / Macbook.

It's a better way to fix this than a workaround such as adding a script to set backlight to a certain level.