I am using ubuntu 18.04 LTS and for some strange reason they omitted the basic functionality to lower the screen brightness in the version for Desktop (because they burn my eyes), for this reason I had to look for alternatives and I found one, using
$ xrandr -q | grep ' connected' | cut -d ' ' -f1 HDMI-0 HDMI-1 $ xrandr --output HDMI-0 --brightness 0.9 $ xrandr --output HDMI-1 --brightness 0.9
I have two monitors connected by hdmi, I use an nvidia gtx1060 video card.
When I execute the command all the screens are turned off and the audio freezes as well (the audio is taken out through the integrated chip of the board, an MSI) and after about 4 seconds everything returns to normal with the brightness changed of the screen that I indicated, after changing the brightness again it does not happen again. Every time I do it for the first time with a screen this blackout happens.
Why is this happening? Is it a driver problem? of the kernel? from wyland?
I am surprised that Ubuntu has omitted such basic functionality as being able to select the monitor from the system settings and being able to change the brightness to one or all the monitors together.