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I've got a Dell Latitude 7410 running on 24.04. I've had this problem since I went from Windows to Linux, same thing on Ubuntu 22.04, 23.10, 24.04 and I also tested LMDE 6 with the same results.

In my display settings there's always an extra display called "Unknown display" set to a resolution of 640x480. It doesn't matter if I have a second display connected or not.

Display settings:

Display settings

The unknown display:

The unknown display

When I have a second monitor connected I'm able to turn off this display, but I can't do this when I only use the built-in screen. This sometimes causes apps to hide in the Unknown Display. The solution I do then is to change display settings to only use a single display.

Does anyone have a solution for this? I've been searching for months now.

Display in xrandr:

DP-1 connected 640x480+5360+0 (normal left inverted right x axis y axis) 0mm x 0mm

CPU: Intel i7-10610U (8) @ 4.900GHz
GPU: Intel Comet Lake-U GT2 [UHD Graphics]

karel
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pavokk
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2 Answers2

2

Disable simpledrm with kernel parameter "Could not switch the monitor configuration" on "None-1-1 connected output"

There is video about simpledrm https://www.youtube.com/watch?v=laFx6RQ3XJ4 (source)

This also worked for me, to disable this extra display with xorg, but kernel parameter seems better How do disable/get rid of PRIME display?

rofrol
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0

Yoga 14 Pro 7 Ultra 9 here with Intel Arc GPU

Only thing that worked for me to remove Unknown 38" display was grub update

From here

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268/comments/32

From this bug

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268

sudo nano /etc/default/grub

add initcall_blacklist=simpledrm_platform_driver_init to where it says:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

so it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash initcall_blacklist=simpledrm_platform_driver_init"

ctrl+O to save and ctrl+X to quit. Back in the terminal write:

sudo update-grub

reboot

PLEASE BE WARNED... This kills my full disk encryption input request on boot.

When I boot I have to count to ten, then blindly type the encryption key and it boots fine. This is a side effect of the work around triggering another bug I think.

Boots fine just no full disk encryption prompt on screen.

The problem looks to be with simpledrm creating a virtual monitor.

If you don't like no encryption prompt, return the grub line back to what it was and update grub again.

Alexis Wilke
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Paul Smith
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