Display artifacts/corruption on Fedora 39

[Tahaan]

Display artifacts/corruption on Fedora 39

[Crashdummyy]

Oh hey I just saw your issues.

A friend of mine got those issues as well ( albeit in gnome ).

They were tied to a VRR workaround so maybe you might need to disable VRR in kde is well.
Doesn't work with displaylink anyways.

For those seeing those issues on gnome.
There might MUTTER_DEBUG_FORCE_KMS_MOD=simple be set.
Without that variable the ghosting is gone

[Tahaan]

I included more information in the original report that seems to be missing from the post now.

The way the issue presents itself is it seems like updates to the DisplayLink connected monitor is slow. There is a lot of "lines" or display corruption on parts ot the screen that is getting repainted. Part of why I think it is performance related is because the problem is worse when a bigger part of the screen is repainted.

A Video is work a thousand words many times over, so here is an older video of the same problem (The video was recorded at a time when I had 1.14.1-2 installed via the RPMs published.

https://youtu.be/uZeN9UesBUY

[firewallzer0]

I am having the exact same issue with my displaylink monitors. Fedora 40, KDE, EVDI v1.14.4, Kernel 6.8.10-300.fc40.x86_64, wayland, NVIDIA GPU, I have looked through the troubleshooting section of displaylink's website. If I use an older displaylink chip, I have no issues. I am currently using the DL-6950 Chipset for dual HDMI monitors. The setup works with no issues under Windows 11 so there is no hardware issue.

echo $XDG_SESSION_TYPE
wayland

sudo dnf list --installed |grep wayland
egl-wayland.x86_64                                   1.1.13-3.fc40                                    @fedora                         
gnome-session-wayland-session.x86_64                 46.0-1.fc40                                      @anaconda                       
kf5-kwayland.x86_64                                  5.115.0-2.fc40                                   @fedora                         
kwayland.x86_64                                      6.0.5-1.fc40                                     @updates                        
kwayland-integration.x86_64                          6.0.5-1.fc40                                     @updates                        
kwin-wayland.x86_64                                  6.0.5-1.fc40                                     @updates                        
libwayland-client.i686                               1.22.0-3.fc40                                    @fedora                         
libwayland-client.x86_64                             1.22.0-3.fc40                                    @anaconda                       
libwayland-cursor.i686                               1.22.0-3.fc40                                    @fedora                         
libwayland-cursor.x86_64                             1.22.0-3.fc40                                    @anaconda                       
libwayland-egl.i686                                  1.22.0-3.fc40                                    @fedora                         
libwayland-egl.x86_64                                1.22.0-3.fc40                                    @anaconda                       
libwayland-server.i686                               1.22.0-3.fc40                                    @fedora                         
libwayland-server.x86_64                             1.22.0-3.fc40                                    @anaconda                       
plasma-workspace-wayland.x86_64                      6.0.5-1.fc40                                     @updates                        
qt5-qtwayland.x86_64                                 5.15.13-1.fc40                                   @anaconda                       
qt6-qtwayland.x86_64                                 6.7.0-1.fc40                                     @updates                        
sddm-wayland-plasma.noarch                           6.0.5-1.fc40                                     @updates                        
wayland-utils.x86_64                                 1.2.0-4.fc40                                     @fedora                         
xisxwayland.x86_64                                   2-4.fc40                                         @anaconda                       
xorg-x11-server-Xwayland.x86_64                      23.2.6-1.fc40                                    @updates                        
xwaylandvideobridge.x86_64                           0.4.0-5.fc40                                     @updates

sudo dnf list --installed | grep nvidia
akmod-nvidia.x86_64                                  3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
kmod-nvidia-6.8.10-300.fc40.x86_64.x86_64            3:550.78-1.fc40                                  @@commandline                   
kmod-nvidia-6.8.9-300.fc40.x86_64.x86_64             3:550.78-1.fc40                                  @@commandline                   
nvidia-gpu-firmware.noarch                           20240513-1.fc40                                  @updates                        
nvidia-modprobe.x86_64                               3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
nvidia-persistenced.x86_64                           3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
nvidia-settings.x86_64                               3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia.x86_64                           3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-cuda.x86_64                      3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-cuda-libs.i686                   3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-cuda-libs.x86_64                 3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-kmodsrc.x86_64                   3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-libs.i686                        3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-libs.x86_64                      3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver
xorg-x11-drv-nvidia-power.x86_64                     3:550.78-1.fc40                                  @rpmfusion-nonfree-nvidia-driver

[firewallzer0]

So I couldn't find a VRR setting in Settings -> Display & Monitor -> Display Configuration but that is what is pulled up when I search for VRR in settings. I do have Adaptive sync on one of my 6 monitors which I set to Never. It is a gsync monitor, also has a high refresh rate of 165 Hz, where as the other monitors have only 60 Hz. I tried setting my VRR policy from the command line but this did not help. I also set all my monitors to 60 Hz. Still no luck. :(
Used the following commands to disable VRR. (Which I am guessing stands for Variable Refresh Rate?)

kscreen-doctor output.1.vrrpolicy.never
kscreen-doctor output.2.vrrpolicy.never
kscreen-doctor output.3.vrrpolicy.never
kscreen-doctor output.4.vrrpolicy.never
kscreen-doctor output.5.vrrpolicy.never
kscreen-doctor output.6.vrrpolicy.never

I have since also purchased a single HDMI DisplayLink output, can't figure out the chipset though. New adapter found here

Additionally I found an older DisplayLink adapter, no idea how old but it uses Mini-USB for input and DVI for the output. This adapter has no issues before or after the VRR settings change.

Appreciate the feedback!
Any other ideas?

[Crashdummyy]

I'm out of ideas in this case, sorry.

[firewallzer0]

Appreciate the help, it got me working on the problem again and I think I solved it.

There is an issue with Wayland and the DisplayLink driver I believe, I started running under X11 and the issue has gone away. (I was having trouble getting X11 running with my config before, which is why I didn't test it before)

Not sure which project to report this to though.

[Crashdummyy]

Appreciate the help, it got me working on the problem again and I think I solved it.

There is an issue with Wayland and the DisplayLink driver I believe, I started running under X11 and the issue has gone away. (I was having trouble getting X11 running with my config before, which is why I didn't test it before)

Not sure which project to report this to though.

Appears that way.
Just out of curiosity.

If you enable the zoom, does it go away ?