Nonexistent display (Unknown Display) messing things up

I've been cracking my head with this one all day, read all there is to be read around the issue (not much to be found on it to be honest: some questions, some blog posts and some unresolved tickets) but I can't seem to find a solution.

I`ve installed ubuntu 14.04 today, upgrading from 12.10 and right out of the box I noticed in the Display settings that it detect a 3rd display that I do not have hooked up to my laptop (that was not there in 12.10). I have a Samsung SyncMaster and the laptop display, but Ubuntu decided to place another Unknown Display next to them (or sometimes over and under them so you can't move them around).

Long story short is that I`m trying to configure nvidia and that unknown display is quite the issue.

I need a way to make ubuntu not detect that and not place it there. I`ve tried finding the name ubuntu detects it as using xrandr and then removing it from the grub as mentioned here, but that didn't work for me.

Some input on tackling this issue will be rewarded in beer.

Cheers!

EDIT: Ok so it seems they are working on it, there is an active ticket about this issue here. They released a fix in the proposed updates ubuntu-drivers-common package.

I've installed it and the phantom display is gone.

EDIT2: I've uninstalled the nvidia driver and went back to nouveau. The Unknown Display is back. Running xrandr -q told me that the ghost display renamed itself from VGA-0 to VGA-1-2. Removing it from grub now and will report if it`s gone.

EDIT3: Its still there.. In the changelog for the ubuntu-drivers-common it says "Ignore CRT displays when using PRIME. This works around systems whose BIOS provides a ghost output (LP: #1296020).", so Im gonna go ahead and reinstall the nvidia driver.

EDIT4: Right, so after installing the nvidia drivers the phantom display is gone. I've reached my goal to be able to comfigure nvidia.

Hope this post helps.

Cheers.

Solution 1:

after installing the nvidia drivers the phantom display is gone. I've reached my goal to be able to comfigure nvidia

The details are in the original post. Hope this saves someone the time i spent investigating the matter.

Cheers.