Brightness fn key adjustment problems
- by npCoder
My brightness function key controls work after setting grub boot parameter to "acpi_osi=" but using them I cannot adjust the brightness higher than around 70% (there is empty bar left over and I can't adjust higher) unless I go to Brightness & Lock settings manually than I can use the slider to adjust it higher... I primarily use intel_backlight to adjust my backlight and I am running Linux kernel 3.14.1 on Ubuntu 14.04 LTS on an ASUS X550LA Laptop
when I try:
cd /sys/class/backlight/intel_backlight
cat max_brightness
937
cat brightness
811
It seems that I can only adjust to a maximum of 811 using the fn brightness controls
If I instead do
cd /sys/class/backlight/acpi_video0
cat max_brightness
10
cat brightness
4
cat actual_brightness
10
With the FN keys actual_brightness is not equal to the value returned from brightness
on acip_video0 (which is always 4) but on intel_backlight actual_brightness = brightness
The adjustment problem seemingly arises because both intel_backlight and acpi_video0 are trying to adjust brightness
