just a comment for those that tried editing the grub file at boot, in my case i edited the grub and added acpi_backlight=vendor, however did not see any effect. having read a few other bug reports I decided to try this again, however using the reverse brightness light keys, and got some success.
so it appears that on Intel machines the backlight is inverted !
just a comment for those that tried editing the grub file at boot, in my case i edited the grub and added acpi_backlight= vendor, however did not see any effect. having read a few other bug reports I decided to try this again, however using the reverse brightness light keys, and got some success.
so it appears that on Intel machines the backlight is inverted !
hope this helps