I am facing an issue with brightness control in my laptop which has Intel HD graphics and Ubuntu 10.10 64-bit. So when I searched for a fix I found that a common suggestion is to edit the GRUB file line, GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"
Documentation for boot parameter acpi_osi
tells:
acpi_osi= [HW,ACPI] Modify list of supported OS interface strings acpi_osi="string1" # add string1 -- only one string acpi_osi="!string2" # remove built-in string2 acpi_osi= # disable all strings
I don't find a reason why this should fix any laptop issue.
So could anyone tell me what the kernel boot option acpi_osi=Linux
do?