I have the exact same problem as the OP, with the “Plasma (Wayland)” session making the display go black for a few seconds, then return to SDDM.
I tried everything in the [Howto] Use wayland with propietary nvidia drivers article, plus I’ve read everything in the KWin/Wayland - KDE Community Wiki article and tried everything there.
Here are the contents of my ~/.local/share/sddm/wayland-session.log file, which is written when trying to start the “Plasma (Wayland)” session from SDDM:
(kwin_wayland:2556): Gtk-WARNING **: 15:48:22.031: cannot open display:
KWin exited with code 1
startplasmacompositor: Shutting down...
startplasmacompositor: Done.
I have:
- Nvidia GTX 1080 Ti
- Nvidia proprietary driver version 470.42.01
- Manjaro unstable branch with the latest available package versions
- everything KDE-and-Wayland-related installed that I could find in research
Here is the output from inxi -G:
Graphics:
Device-1: Intel HD Graphics 530 driver: i915 v: kernel
Device-2: NVIDIA GP102 [GeForce GTX 1080 Ti] driver: nvidia v: 470.42.01
Device-3: Logitech C922 Pro Stream Webcam type: USB
driver: snd-usb-audio,uvcvideo
Display: x11 server: X.Org 1.20.12 driver: loaded: nvidia resolution:
1: 1920x1200~60Hz 2: 1920x1080~60Hz
OpenGL: renderer: NVIDIA GeForce GTX 1080 Ti/PCIe/SSE2
v: 4.6.0 NVIDIA 470.42.01
Here is the output of yay -Qs wayland (meaning packages that are wayland-related that are installed on my machine):
local/egl-wayland 1.1.7-1
EGLStream-based Wayland external platform
local/kodi 19.1-5
A software media player and entertainment hub for digital media
local/kwayland 5.84.0-1 (kf5)
Qt-style Client and Server library wrapper for the Wayland libraries
local/kwayland-integration 5.22.3-1 (plasma)
Provides integration plugins for various KDE frameworks for the wayland
windowing system
local/kwayland-server 5.22.3-1 (plasma)
Wayland server components built on KDE Frameworks
local/layer-shell-qt 5.22.3-1 (plasma)
Qt component to allow applications to make use of the Wayland wl-layer-shell
protocol
local/lib32-wayland 1.19.0-1
A computer display server protocol
local/libva 2.12.0-1
Video Acceleration (VA) API for Linux
local/plasma-wayland-protocols 1.3.0-1
Plasma Specific Protocols for Wayland
local/plasma-wayland-session 5.22.3-1
Plasma Wayland session
local/qt5-wayland 5.15.2+kde+r29-1 (qt qt5)
Provides APIs for Wayland
local/sddm 0.19.0-6
QML based X11 and Wayland display manager
local/wayland 1.19.0-1
A computer display server protocol
local/wayland-protocols 1.21-1
Specifications of extended Wayland protocols
local/waylandpp 0.2.8-1
Wayland C++ bindings
local/wrapland 0.522.0-1
Qt/C++ library that wraps and mediates the libwayland client and server API
local/xorg-xwayland 21.1.2-1 (xorg)
run X clients under wayland
I’ve tried researching this online extensively and haven’t been able to find a solution. I really want to try Plasma with Wayland. Any help, including asking me for things to try, would be greatly appreciated. Thanks for reading!