Arch Linux

cphyc

Member

Registered: 2015-01-06

Posts: 19

Adding VIRTUAL output using intel drivers

Hi all,

Problem

I was following https://bbs.archlinux.org/viewtopic.php?id=191555 to use a second computer of mine as a display, relying on VNC. This requires enabling one of the disconnected outputs using xrandr with a custom mode that matches the screen size of the other computer.
The issue is that I cannot create a virtual output.

I have tried two different approaches.

Adding a mode with xrandr

So far I have tried the following

$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 293mm x 162mm
   1920x1080     60.03*+  48.03  
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
$ xrandr --addmode DP-1 1920x1080
$ xrandr --output DP-2 --mode 1920x1080 --right-of eDP-1
xrandr: Configure crtc 1 failed

I have exactly the same issue if I use DP-1 instead of DP-2. Following this thread, it seems that my graphic card (integrated Intel HD) does not support native VGA output (I do not have any VGA output anyway) but I do not know if it is related.

Restoring the "VIRTUAL" output using X config files

Another thing I have tried is to bring back the "VIRTUAL1" output and activate it. For that, I created

# /usr/share/X11/xorg.conf.d/01-dummy-monitor.conf
Section "Device"
    Identifier      "Configured Video Device"
    Driver "intel" 
    Option "TearLess"   "1"
EndSection

Section "Monitor"
        Identifier      "Configured Monitor"
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
EndSection

but now my X sessions doesn't start anymore. The output of journactl gives me this error message.

System setup

Computer: Dell XPS 13 7390 with "Intel UHD Graphics with shared graphics memory" (couldn't find more relevant info on the Dell website)
Output of journalctl (without 01-dummy-monitor.conf): here
Installed packages: mesa, xf86-video-intel is not installed.

Last edited by cphyc (2020-04-14 16:44:23)