DisplayLink Club3D CSV-1477 video adapter: mouse can go off-screen when using multiple monitors

[ElectricRCAircraftGuy]

Quick summary

I can move my mouse off-screen into the sections in yellow here. I shouldn't be able to move my mouse past the edge of any monitor, so this is a definite bug. When not using this adapter at all, but using the same computer, monitors, and setup, I do not see this bug, and my cursor is properly blocked from exiting the edge of all monitors.

Details

• This adapter: Club3D CSV-1477 USB 3.0 Type A to Dual Display Port 1.2 4K 60Hz External Graphics Video Adapter for Multiple Monitors
• OS: Ubuntu 22.04 (Dell Latitude 5570) and Ubuntu 20.04 (Dell Latitude 7490); I tested and proved this bug on 2 separate computers
• DisplayLink driver: 5.8.0-33 (as shown by sudo apt install displaylink-driver)

I installed the DisplayLink driver per my instructions here: https://askubuntu.com/a/1486986/327339:

# Make this directory if it doesn't exist, and cd into it
mkdir -p ~/Downloads/Install_Files/DisplayLink
cd ~/Downloads/Install_Files/DisplayLink

# Download the Ubuntu APT package provided by Synaptics.com, the official 
# makers of DisplayLink
wget https://www.synaptics.com/sites/default/files/Ubuntu/pool/stable/main/all/synaptics-repository-keyring.deb

# Install the DisplayLink APT package keyring
sudo apt install ./synaptics-repository-keyring.deb

# Update your APT package cache
sudo apt update

# Install the DisplayLink driver provided by Synaptics.com, the official source
sudo apt install displaylink-driver

In certain multi-monitor configurations, however, I can move the mouse off of the monitors into the dead corner spaces between monitors. I should be blocked from moving the mouse off-screen, but again, the bug is that I am not blocked from doing so. The problem only seems to exist when driving really high-resolution monitors (ex: 4k 32"), while other monitors are plugged into my computer too, even by other means.

Here is the most basic monitor setup exhibiting this bug (I removed a monitor for the purposes of this demo):

1. My laptop screen: 1920 x 1200 59.95 Hz
2. My 32" 4k AOC monitor: 3840 x 2160 60.00 Hz connected via a DP cable into the Club3D DisplayLink adapter.
3. this monitor 2560 x 1440 59.95 Hz plugged in via an HDMI cable to a separate HDMI to USB-C adapter

When in this configuration, I can move the mouse off the screen to all the corners shown in yellow. Again, this is the bug. I should not be allowed to move the mouse into these areas!:

When using a single external monitor in addition to my laptop screen, this bug does not seem to occur.

• Email the DisplayLink people to report this: technical-enquiries@synaptics.com
• Email info@club-3d.com too. https://www.club-3d.com/en/detail/2413/usb3.2_gen1_type_a_to_displayportt1.2_dual_monitor_4k60hz_video_splitter/

[ElectricRCAircraftGuy]

Email reply from: technical-enquiries@synaptics.com

DisplayLink provides a support tool that can check for common issues and gathers up system information, useful to DisplayLink in diagnosing problems. Before submitting a bug to DisplayLink, please follow the steps below to provide the right information.

The support tool produces a zip file containing information stored in plain text. The file and log text are not encrypted (apart from the DisplayLink software log files) to allow you to see what data has been collected.

1. Download the Linux support tool.
2. dlsupporttool.zip contains 2 executables, dependent on the OS version.
3. Run the tool on your PC after the problem has occurred, using the following command: sudo ./DLSupportTool
4. The zip file of information will be saved in a zip file in the current directory.
5. Close the tool and respond to this email with the logfile attached. The file name will be similar to DLSupportTool_Output_202x-06-05T182032.408950.zip

DLSupportTool usage:

-h, --help	shows help
--debug	    enables advanced logging and exits
--nodebug	disables advanced logging and exits

The Linux DisplayLink Support Tool gathers the following system information:

1. DisplayLink Software installed
2. DisplayLink devices connected to the PC
3. Details about the PC spec
4. DisplayLink Software log files and crash dumps
5. System processes output and crash dumps related to USB and video (e.g. xrandr, dmesg)

[ElectricRCAircraftGuy]

My tasks:

1. with the issue presenting itself on my Ubuntu 20.04 computer, run sudo x64/DLSupportTool and email the autogenerated zip file to Kate C at technical-enquiries@synaptics.com
2. do the same on my Ubuntu 22.04 computer

[ElectricRCAircraftGuy]

Ubuntu 22.04 results on Dell Precision 5570 high-end 20-core laptop

Ok, when I just plugged in those two monitors again, I did not get the mouse-going-offscreen behavior. So, I plugged in a 3rd monitor, and now I do.

Here's my configuration:

Yellow shows where I can move my mouse off-screen, but should not be able to:

Monitors:

1. My laptop screen 1920x1200 59.95Hz lanscape
2. 4k 32" AOC curved display 3840x2160 60.00Hz landscape - DP cable into Club3D DP to USB-A adapter
3. 2k 2560x1440 59.95 Hz protrait left - HDMI cable into HDMI to DP adapter into Club3D DP to USB-A adapter
4. 1280x1024 60.02 Hz landscape - via a separate HDMI to USB-C adapter

The Club3D DP to USB-A adapter is plugged into a USB 3.0 type A hub which is connected to the laptop via a USB-C port.

Log file generation command: sudo x64/DLSupportTool
File: DLSupportTool_Output_2023-10-06T16:36:07.572767 [Ubuntu 22.04].zip - I'll email it to Kate C at technical-enquiries@synaptics.com

[ElectricRCAircraftGuy]

Ubuntu 20.04 results on weaker 8-core Dell Latitude 7490 laptop

Same: when I just plugged in those two monitors again, I did not get the mouse-going-offscreen behavior as before. So, I plugged in a 3rd monitor, and now I do.

Here's my configuration:

Yellow in the Ubuntu 22.04 comment above shows where I can move my mouse off-screen, but should not be able to.

Monitors:

1. My laptop screen 1920x1080 60.01 Hz landscape
2. 1280x1024 60.02 Hz landscape - via HDMI cable straight into the laptop
3. 4k 32" AOC curved display 3840x2160 60.00Hz landscape - DP cable into Club3D DP to USB-A adapter
4. 2k 2560x1440 unknown Hz portrait left - HDMI cable into HDMI to DP adapter into Club3D DP to USB-A adapter

The Club3D DP to USB-A adapter is plugged straight into a USB 3.0 type A port in the laptop.

Log file generation command: sudo x64/DLSupportTool
File: DLSupportTool_Output_2023-10-06T17:01:06.165973 [Ubuntu 20.04].zip - I'll email it to Kate C at technical-enquiries@synaptics.com

Driver installation instructions

Note: here is how I installed the driver on this computer: Full instructions: installing displaylink-driver on Ubuntu 20.04 (also applies to 22.04 or later).

[ElectricRCAircraftGuy]

My latest email to Kate:

And for my Ubuntu 20.04 computer, which has the same problem on the adapter, see this post: #20 (comment)

And my zip file for it is attached: "DLSupportTool_Output_2023-10-06T17:01:06.165973 [Ubuntu 20.04].zip"

I've also attached an extra zip file on this same computer where the issue is NOT present, in a different monitor configuration: "DLSupportTool_Output_2023-10-06T16:17:47.774128 [issue NOT present].zip"

[ElectricRCAircraftGuy]

Another setup with the problem:

Ubuntu 22.04 with 2 monitors (only 1 in the Club3D adapter)

1. OS: Ubuntu 22.04
2. Laptop: Dell Precision 5570

Monitors:

1. laptop 1920x1200 59.95 Hz
2. 4k 3840x2160 60.00 Hz into the Club3D adapter via DP cable
3. 2k 2560x1440 59.95 Hz: USB-C cable into USB-C port on laptop

Mouse can go off-screen in this yellow region:

• emailed diagnostics file: DLSupportTool_Output_2023-10-09T16:36:20.701363.zip

---

My email describing this:

Kate, my replies:

And just to be sure, if you only have two monitors connected to the Club 3D adapter everything is okay but as soon as you add a 3rd monitor (the one connected directly to the computer) the issue starts?

No, sometimes it happens with only 2 monitors plugged in. 

Would you be able to check this problem with directly connected displays (on desktop PC with larger number of outputs)?

I don't have a desktop PC (I haven't since 2003), but to answer the question: with directly-connected displays, rather than going through the Club3D adapter, the problem is not present. The problem is only present with the Club3D adapter in use. Here's a scenario: #20 (comment)

Another diagnostics file for this scenario is attached. 

Thanks!

Gabriel Staples

[ElectricRCAircraftGuy]

To clarify for the setup just above: when I remove the Club3D adapter entirely, and direct-connect the 4k monitor via a DP to USB-C adapter, and direct-connect the 2k monitor via a USB-C cable straight from the monitor, I do not get the above aberrant behavior where the mouse can go off-screen.

I can also direct connect the 2k monitor via an HDMI cable to an HDMI to USB-C adapter, and again, I do not get the aberrant behavior. I only Get it when using the Club3D adapter.

Here is the setup that does not have the problem:

1. laptop 1920x1200 59.95 Hz
2. 2k 2560x1440 59.95 Hz connected straight to laptop via USB-C cable
3. 4k 3840x2160 60.00 Hz connected to laptop via DP to USB-C adapter

Here is the other setup that does not have the aberrant behavior:

1. laptop 1920x1200 59.95 Hz
2. 4k 3840x2160 60.00 Hz connected to laptop via DP to USB-C adapter
3. 2k 2560x1440 59.95 Hz connected to laptop via HDMI to USB-C adapter

The mouse-going-offscreen aberrant behavior is only present when using the Club3D adapter, and even then, only in certain configurations as described above.

[ElectricRCAircraftGuy]

Here, with only monitor 2 in this image being connected through the Club3D adapter, and all other monitors being connected through USB-C interfaces or adapters, the aberrant behavior is also not present! It's working fine in this setup:

[ElectricRCAircraftGuy]

Upstream xserver bug report that the DisplayLink Technical Support team opened up and emailed me about: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1600