All Linux NVIDIA Drivers newer than 440.1 Duplicate / Split USB-C Video with a Green Line in-between

We have a Video Game running in Mint 19.3 (Kernel 5.4.0-70) on a B450 Mini-iTX Motherboard with 8GB DDR4 3200 memory, Ryzen 5 1600x CPU, 64GB Optane NVMe and one of several types of NVIDIA RTX 2080 graphics cards.

We run 4K @60Hz on multiple monitors; a Primary monitor is always present and connected via HDMI, but in some cabinet configurations, we have a second monitor connected via USB-C (DisplayPort) that displays an inverted view (think Battleship arrangement, back-to-back) where the player stations are on opposite borders of the display.

Up through Linux drivers 440.1 everything works perfectly. Past that, (currently 460.39) and needed for 30xx cards, the USB-C video output gets crazy. The image is duplicated on the monitor and squished to half-height, with a thick green bar across the middle. Note that in the pic below, we extended the desktop, as opposed to the arrangement we run in Production

To see the game “in action” with this problem, in our ENG lab, please see the YouTube video here:

Oddly enough, we only see this behavior when we ONLY have HDMI + USB-C. If we add a DisplayPort-connected tertiary monitor, the problem goes away!:

Due to posting limitations, I have to cut this post off, but I will try to add another right behind this one.

We have tried to pull as much information as possible to assist NVIDIA or anyone else interested in this mystery. Let’s start with the requisite nvidia-bug-report.log.gz file

nvidia-bug-report.log.gz (284.2 KB)

We also have screenshots of the various nvidia-setting UI screens here:

NVIDIA-Settings.rar (3.2 MB)

Our xorg.conf file lives in 2 places; /etc/X11 and /usr/share/X11/xorg.conf.d but we keep the files in sync:

xorg.conf (1.7 KB)

We also saw a post that has an amazing concatenation of commands starting with lspci, so including that:

lspci-long (60.6 KB)

We are in full production of several thousand machines and need a single OS to support both 3060 ti cards and the 2080 cards that still have the USB-C, which is so-far the only way we’ve done dual-screen, via USB-C to HDMI Adapter cables.

I hope we have not overloaded this topic with too much data. If someone wants to peer directly into the system, it has TeamViewer installed, and a DM to chris.cummings@paceomatic.com would be awesome. We can get you hooked right in.

Thanks for taking a look!

This has been reported before but so far nvidia didn’t respond
https://forums.developer.nvidia.com/t/no-picture-on-1-dual-monitor/173179?u=generix
https://forums.developer.nvidia.com/t/ubuntu-20-04-2070s-nvidia-460-sets-one-monitor-into-2560x2922-30fps-and-does-split-screen-mirror/174193?u=generix
https://forums.developer.nvidia.com/t/dual-gpu-triple-monitors-horizontal-screen-split/165635?u=generix
The underlying problem seems to be the nvidia driver >440 having problems with a lot of active DP2HDMI converters.

Thanks for the very fast reply, generix! Sorry if I am duplicating a problem already being seen.