Problem: xrandr usage
Tried to change gamma with the following:
Q: What is 'crtc' and how to know it?$ xrandr --output LVDS-1 --gamma 0.3:0.3:0.3
xrandr: Need crtc to set gamma on.
Q: What is 'crtc' and how to know it?$ xrandr --output LVDS-1 --gamma 0.3:0.3:0.3
xrandr: Need crtc to set gamma on.
xrandr --listactivemonitors
0: +*VGA-1 1280/376x1024/301+0+0 VGA-1
1: +HDMI-1 1366/609x768/347+0+0 HDMI-1
sk@Petrovich-X200CA:~$ xrandr --output VGA-1 --gamma 0.3:0.3:0.3
apt install xcalib xbacklight
xcalib -gammacor 2.2 -a
Note also that xbacklight appears to be somewhat broken...xbacklight -set 30
ls /sys/class/backlight/
intel_backlight
ls /sys/class/backlight/intel_backlight
actual_brightness bl_power brightness device max_brightness power subsystem type uevent
cat /sys/class/backlight/intel_backlight/max_brightness
208
echo 60 | sudo tee /sys/class/backlight/intel_backlight/brightness
:~$ xcalib -gammacor 2.2 -a
Error - unsupported ramp size 0