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I installed newest cinnamon 24.04, and while in previous version everything worked just fine, in this version I have a 'ghost monitor', to which the cursor can wander, but which cannot be turned off in Display settings.

If I open nvidia settings, I see this:

dialog with two display options, of which the selected one is PRIME 1920x1080

So there is some prime display, which cannot be controlled. I tried a recommendation to add a kernel parameter

initcall_blacklist=simpledrm_platform_driver_init

but this just makes the OS unbootable.

I guess this was induced by upgrading lenovo firmware, which I probably can downgrade back. But is there any better solution? How to get rid of this PRIME display, which is rather sub-prime, since it does not display anything and just makes your work harder.

Zanna
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Martin Mucha
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  • Adding kernel parameter this way worked for me https://askubuntu.com/questions/1509661/could-not-switch-the-monitor-configuration-on-none-1-1-connected-output/1514074#1514074 – rofrol Jun 06 '24 at 21:30
  • I also have a mysterious "Unknown Display" (in addition to my actual display) on Ubuntu 22.04.4 LTS with an nvidia graphics card, with a single monitor connected via DisplayPort (on a desktop computer, i.e. no built-in display). – ingo-m Sep 05 '24 at 10:39

1 Answers1

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The work around can be found in @ maarallez's answer in this Reddit thread: Weird second display: nvidia PRIME Display (some formatting added by me):

You can disable the ghost screen by writing a short config file.

First, open a terminal and run xrandr to identify your screens. Take note of the name of the ghost device (e.g. HDMI-0, DP-0, etc.); mine was None-1-1.

Then create your config file:

sudo gedit /etc/X11/xorg.conf.d/10-monitor.conf

Paste the following, making sure to replace the VGA1 with the name you identified in the previous step:

Section "Monitor"
    Identifier "VGA1"
    Option "Ignore" "true"
EndSection

Save the file and reboot.

Alexis Wilke
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amar
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    Happened to me as well after upgrading to cinammon 24.04, and this fix worked for me as well and interestingly was also called None-1-1 – Timo Huovinen Aug 13 '24 at 07:32
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    If it re-appears, as it probably will, re-check the configuration file: /etc/X11/xorg.conf.d/10-monitor.conf For me it was deleted during updates, so that I can enjoy unusable invisible annoying fake monitor again :) – Martin Mucha Aug 19 '24 at 17:23
  • Thanks. This solution worked for me on a desktop computer running Ubuntu 22.04.4 LTS with an nvidia graphics card, with a single monitor connected via DisplayPort. – ingo-m Sep 05 '24 at 10:49
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    Correct me if I am wrong, but 24.04 uses Wayland. This solution assumes X11. Any ideas how to achieve the same thing on Wayland? – Paloha Dec 20 '24 at 08:52