The brightness control in the settings does not work. I have an Intel® HD Graphics 4000 (on a i5-3570K Processor) and run Ubuntu 14.04.03.
I followed the instruction given in https://wiki.ubuntu.com/Kernel/Debugging/Backlight for Intel HD, which is to create a file
Section "Device" Identifier "Intel Graphics" Driver "intel" Option "AccelMethod" "sna" Option "Backlight" "intel_backlight" # use your backlight that works here BusID "PCI:0:2:0" EndSection
After a reboot it still does not work.
Also, I get
$ ls /sys/class/backlight/ acpi_video0
Am I not supposed to get some Intel stuff instead?
From other instruction found in https://askubuntu.com/a/481501/481818 I added
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"
and reboot, but still no brightness control.
Anybody can help?