The other day, I got tired of waiting for the 18.04 upgrade option for my Ratel Pro, and went ahead with a full install from the ISO. This proceeded without incident, except for one thing: I have the screen dim (not lock) after 15 minutes. In 17.10, this worked very well, with my HDMI-connected monitor going to an "off" state after 15 minutes of inactivity. But now, under 18.04, it was just darkening, with the mouse pointer still visible. Before seeking a fix for this, I remembered that I had not installed system76-driver since the 18.04 install, so I went ahead and did that. Suddenly, the dimming started working properly again. When I "run" the system76-driver, it says that "All of the drivers for this system are provided by Ubuntu", which seems to imply that there is no need for this package on my system. Does installing it actually do more than install drivers? Is it really responsible for fixing my dimming problem? Is there a setting somewhere that lets you specify how you would like "dimming" to work?