Fedora 34 XFCE: dual monitor hassle
 

Hi all,
I have a relatively new PC with dual monitors that runs Fedora 34 with XFCE.
It is a Lenovo M920 ThinkCentre, with dual display port outputs. I have two monitors attached to it and it uses the on-board Intel UHD 630 graphics card.

I configured my monitors to span the desktop across both of them. After boot, this normally works fine. However, after monitors went to sleep due to inactivity, as soon as they resume the monitors randomly switch to "mirror" i.e. I have one small desktop, displayed the same on both monitors.
It is so annoying. Furthermore I don't have a XFCE panel or launchers on the 2nd monitor, so if this one gets mirrored, I have no possibility of accessing the "XFCE Display Settings" dialog to switch off mirroring!
Because I never switch off my PC, my daily ritual every morning is to switch off mirroring. Normally I put the XFCE Display Settings dialog on one monitor before I leave the PC. When I return and XFCE has decided to switch on mirroring, I can readily disable it again. This has become my daily morning routine.

The annoying thing is, that with my old PC the two monitors never went into mirror mode, but since I got this new PC it happens at least once a day.
Is it somehow possible to completely disable the mirror option? how can I find out why it switches on mirroring?

One way to do this is to write a video config file and put it in /etc/X11/xorg.conf.d

I had one named 20-video.conf there, which set up stuff, but it's out of date. You'll find examples but basically put the Video Section from 'man xorg.conf.' I have ServerLayout, Monitor, Device & Screen sections I have a 1600×900, & 1920×1080, so I have a virtual screen size of 3520×1080. The hdmi screen has an option "Position 1601 0" and I have "RightOf Screen 0"

Now for sure some of the options I used have vanished, and throw errors, but you get the idea.

I haven't had this specific problem, but I do have simple scripts to alter my monitor configuration on the fly. For example, I have a tabletPC screen which I wish to invert upside-down when I'm using it for drawing stuff but I wish to change to right-side-up when I'm using it like a traditional laptop.

My shell scripts simply use xrandr to define the desired video modes and options (as well as, in my case, remapping the WACOM input to invert or not). This is the sort of thing it looks like:

In this example, it sets up DVI-0 to 1600x900 resolution, DVI-1 to 1280x1024 resolution, with DVI-1 to the right of DVI-0; both share the same bottom edge (900+124 = 1024+0).

So, set up the monitors just how you like, and then use the following command to see how it is set up:

Make a shell script to run the desired xrandr command, and save it to "DualMon.sh". Use "chmod 755 DualMon.sh" to make it executable, and then create a Launcher to run this command.

It's not a fully automated thing, but it's quick and easy to just click on the Launcher to get the monitors back the way you want.