Bug 511685

Summary: xternal 4K monitor constantly disconnects/reconnects every ~5 s under Fedora 43 KDE Wayland (Intel + NVIDIA GM107 Quadro M1200)
Product: [Plasma] KScreen Reporter: bernd.brier
Component: commonAssignee: kscreen-bugs-null <kscreen-bugs-null>
Status: REPORTED ---    
Severity: major CC: bernd.brier, sadikugursoy
Priority: NOR    
Version First Reported In: git-stable-Plasma/6.3   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: drm_status snampshot
gpu_info.txt
kde_wayland_journal.log
kde_wayland_monitor_dmesg.log
/var/log/dnf5.log.1

Description bernd.brier 2025-11-05 19:47:32 UTC
Created attachment 186529 [details]
drm_status snampshot

** System configuration **

Distribution:  Fedora release 43 (Forty Three)

Kernel: 6.17.6-300.fc43.x86_64

Desktop environment:
- plasmashell 6.5.1
- kwin 6.5.1

GPU Hardware:
$sudo lspci -nn | grep -E "VGA|3D"
00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics P630 [8086:591d] (rev 04)
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] [10de:13b6] (rev a2)

Driver info:
$ rpm -qa | grep nvidia
lsmod | grep -E "nvidia|nouveau|i915"
inxi -Gxx
kmod-nvidia-6.17.4-200.fc42.x86_64-580.95.05-1.fc42.x86_64
kmod-nvidia-6.17.6-200.fc42.x86_64-580.95.05-1.fc42.x86_64
xorg-x11-drv-nvidia-kmodsrc-580.95.05-1.fc43.x86_64
xorg-x11-drv-nvidia-cuda-libs-580.95.05-1.fc43.x86_64
nvidia-modprobe-580.95.05-1.fc43.x86_64
nvidia-persistenced-580.95.05-1.fc43.x86_64
xorg-x11-drv-nvidia-libs-580.95.05-1.fc43.x86_64
nvidia-settings-580.95.05-1.fc43.x86_64
xorg-x11-drv-nvidia-580.95.05-1.fc43.x86_64
akmod-nvidia-580.95.05-1.fc43.x86_64
xorg-x11-drv-nvidia-cuda-580.95.05-1.fc43.x86_64
xorg-x11-drv-nvidia-power-580.95.05-1.fc43.x86_64
nvidia-gpu-firmware-20251021-1.fc43.noarch
kmod-nvidia-6.17.6-300.fc43.x86_64-580.95.05-1.fc43.x86_64
nvidia_drm            155648  0
nvidia_modeset       1929216  1 nvidia_drm
nvidia_uvm           4059136  0
nvidia              111534080  3 nvidia_uvm,nvidia_drm,nvidia_modeset
drm_ttm_helper         16384  1 nvidia_drm
i915                 5369856  56
i2c_algo_bit           20480  1 i915
drm_buddy              32768  1 i915
ttm                   135168  2 drm_ttm_helper,i915
drm_display_helper    331776  1 i915
cec                   106496  2 drm_display_helper,i915
video                  81920  4 dell_wmi,dell_laptop,i915,nvidia_modeset
Graphics:
  Device-1: Intel HD Graphics P630 vendor: Dell driver: i915 v: kernel
    arch: Gen-9.5 ports: active: eDP-1 empty: DP-1, DP-2, DP-3, HDMI-A-1,
    HDMI-A-2, HDMI-A-3 bus-ID: 00:02.0 chip-ID: 8086:591d
  Device-2: NVIDIA GM107GLM [Quadro M1200 Mobile] vendor: Dell
    driver: nvidia v: 580.95.05 arch: Maxwell pcie: speed: 2.5 GT/s lanes: 16
    ports: active: none empty: DP-4, DP-5, DP-6, VGA-1, eDP-2 bus-ID: 01:00.0
    chip-ID: 10de:13b6
  Device-3: Sunplus Innovation Integrated_Webcam_HD driver: uvcvideo
    type: USB rev: 2.0 speed: 480 Mb/s lanes: 1 bus-ID: 1-11:9
    chip-ID: 1bcf:2b96
  Display: wayland server: Xwayland v: 24.1.9 compositor: kwin_wayland
    driver: gpu: i915 display-ID: 0
  Monitor-1: eDP-1 model: Sharp 0x1430 res: 3840x2160 hz: 60 dpi: 282
    diag: 397mm (15.6")
  API: EGL v: 1.5 platforms: device: 0 drv: nvidia device: 2 drv: iris
    device: 3 drv: swrast gbm: drv: nvidia surfaceless: drv: nvidia wayland:
    drv: iris x11: drv: iris inactive: device-1
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: intel mesa v: 25.2.5 glx-v: 1.4
    direct-render: yes renderer: Mesa Intel HD Graphics P630 (KBL GT2)
    device-ID: 8086:591d display-ID: :0.0
  API: Vulkan v: 1.4.321 surfaces: N/A device: 0 type: integrated-gpu
    driver: mesa intel device-ID: 8086:591d device: 1 type: discrete-gpu
    driver: nvidia device-ID: 10de:13b6 device: 2 type: cpu
    driver: mesa llvmpipe device-ID: 10005:0000
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: nvidia-settings,nvidia-smi
    wl: wayland-info x11: xdriinfo, xdpyinfo, xprop, xrandr

*** Problem description ***

When connecting a 4K external monitor (via DisplayPort or HDMI) to a laptop with hybrid Intel + NVIDIA graphics under KDE Plasma Wayland on Fedora 43, the screen connects successfully, displays an image for ~5 seconds, then disconnects — and reconnects again in a loop.
This repeats indefinitely.

The same setup works perfectly under GNOME Wayland on the same Fedora installation.

It also worked under Fedora 42 KDE Wayland before upgrade.

The issue occurs immediately after login and persists regardless of NVIDIA driver version (tested 555 and 560 series).

** Reproduction steps: **
🔍 Reproduction steps

-Boot Fedora 43 with KDE Wayland session.
-Log in using Wayland (not X11).
-Connect external 4K monitor via HDMI or DisplayPort.-
-Observe that:
-Display appears for ~5 seconds.
-Then disconnects (black screen).
-Then reconnects.
-Loop repeats endlessly.

** Collected logs **

(1)Kernel and DRM events
 Run this before connecting the monitor:
(2) System journal (KWin, Plasma, Display, NVIDIA)
sudo journalctl -b | grep -iE "kwin|plasma|wayland|nvidia|intel|drm" > ~/kde_wayland_journal.log
(3) Session logs:
cp ~/.local/share/sddm/wayland-session.log ~/wayland-session.log 2>/dev/null
cp ~/.local/share/kwin-wayland-*.log ~/kwin-wayland.log 2>/dev/null
(4) Active Display snapshot:
sudo cat /sys/class/drm/*/status > ~/drm_status_snapshot.txt
(5) GPU and driver info 
inxi -Gxx > ~/gpu_info.txt


**  Expected behavior **

The external 4K monitor should remain connected and display a stable image, as it does under GNOME Wayland on the same system.

** Actual behavior **

Monitor repeatedly disconnects and reconnects every few seconds. The desktop becomes temporarily unresponsive during each cycle.
Comment 1 bernd.brier 2025-11-05 19:48:02 UTC
Created attachment 186530 [details]
gpu_info.txt
Comment 2 bernd.brier 2025-11-05 19:48:30 UTC
Created attachment 186531 [details]
kde_wayland_journal.log
Comment 3 bernd.brier 2025-11-05 19:49:03 UTC
Created attachment 186532 [details]
kde_wayland_monitor_dmesg.log
Comment 4 sadik ugursoy 2025-11-07 12:55:16 UTC
Something similar happens to my monitor as well. It is a 1080p 144hz monitor, connected by Display Port, and I observe the same 5-ish seconds display and disconnect on various occasions:
1. When using an application in full-screen
- This includes full-screen video games, full-screen YouTube videos, spectacle's screen capture mode and even viewing an image from telegram client in enlarged view. Any app that is not full-screen works fine in this case.
2. When pc stays on idle and screen shuts down
- This is not consistent but sometimes happens. In this case, even when there are no full-screen applications the display keeps disconnecting. This makes it impossible to use the pc at all. Shutting down the screen is no help.

I have a solid fix that works every time. For #1, follow the steps:
1. Open Display Configuration (hitting Super key breaks the full-screen render, so display comes back I think)
2. Set refresh rate to 59.95 Hz (others might work too i didn't test)
3. Wait for the Apply/Revert changes pop-up and choose revert
This fixes the issue and apps can be used in fullscreen without issues; until it is broken again, by whatever reason. It can break during the same session too. 

For #2, I didn't event manage to open Display Configuration for the first few occurrences because in that case, the display never comes back on. But after some trials, I noticed that moving the mouse cursor fast (that makes the cursor go BIG) fixes the issue as long as it stays big. Display just comes back. You can apply the same steps for case#1 while wiggling the mouse! It fixes the issue.

Not sure if this would help but, I made system updates at: 
2025.11.06
2025.11.02

The issue was started before 2025.11.02, I don't remember when I did my last update before that, but it should be the weekend prior. Probably 2025.10.26. The issue I mentioned at #2 only started after my last update.

Distro: EndeavourOS

Desktop Env:
plasmashell 6.5.1
kwin 6.5.1 (wayland)

GPU Hardware:
sudo lspci -nn | grep -E "VGA|3D"
29:00.0 VGA compatible controller [0300]: NVIDIA Corporation TU106 [GeForce RTX 2060 Rev. A] [10de:1f08] (rev a1)

Driver:
nvidia-smi
...
NVIDIA-SMI 580.95.05              Driver Version: 580.95.05      CUDA Version: 13.0 
...
Comment 5 sadik ugursoy 2025-11-10 14:14:22 UTC
I don't experience the full-screen disconnect after the latest update, but the second issue I mentioned (caused by "turn of screen after N minutes") is still here. The solution still works (change and revert display frequency). Updated system configuration:

Distro: EndeavourOS

Desktop Env:
plasmashell --version
plasmashell 6.5.2

kwin_wayland --version
kwin 6.5.2

GPU Hardware:
sudo lspci -nn | grep -E "VGA|3D"
29:00.0 VGA compatible controller [0300]: NVIDIA Corporation TU106 [GeForce RTX 2060 Rev. A] [10de:1f08] (rev a1)

Driver:
nvidia-smi
...
NVIDIA-SMI 580.105.08             Driver Version: 580.105.08     CUDA Version: 13.0 
...
Comment 6 bernd.brier 2025-11-11 21:40:09 UTC
I had some updates today. And suddenly the monitor works as it should. :-) Hope it stays like this.
Comment 7 bernd.brier 2025-11-11 21:54:56 UTC
Created attachment 186713 [details]
/var/log/dnf5.log.1

This is the /var/log/dnf5.log.1 which covers the period, when the monitor picture magically became stable. 

Maybe these actions fixed it:
2025-11-11T21:00:01+0000 [10615] INFO RPM callback install start "kmod-nvidia-6.17.7-300.fc43.x86_64-3:580.95.05-1.fc43.x86_64" total 154148876
2025-11-11T21:00:01+0000 [10615] INFO RPM callback install stop "kmod-nvidia-6.17.7-300.fc43.x86_64-3:580.95.05-1.fc43.x86_64" amount 154148876 total 154148876
2025-11-11T21:00:02+0000 [10615] INFO RPM callback start %post scriptlet "kmod-nvidia-6.17.7-300.fc43.x86_64-3:580.95.05-1.fc43.x86_64"
2025-11-11T21:00:13+0000 [10615] INFO RPM callback stop %post scriptlet "kmod-nvidia-6.17.7-300.fc43.x86_64-3:580.95.05-1.fc43.x86_64" return code 0