SUMMARY I have a Thinkpad T470 with a docking station. When I plug in the laptop the second screen is not recognized with kwin_wayland. With kwin_x11 everything works. STEPS TO REPRODUCE 1. Disconnect laptop from the dock (and second screen). 2. Start Wayland session (per SDDM). Everything works so far. 3. Plug in the laptop into the dock. OBSERVED RESULT Nothing happens (except that the battery is loading now and the network changes to Ethernet). EXPECTED RESULT Second screen will be recognized. Monitor setup will be shown. (If I go into the System Settings the monitor is also not recognized.) SOFTWARE/OS VERSIONS Linux/KDE Plasma: Gentoo, Kernel 4.19.27, Kwin 5.15.5 (I'll update it ASAP). (available in About System) KDE Plasma Version: 5.15.5 KDE Frameworks Version: 5.58.0 Qt Version: 5.12.3 ADDITIONAL INFORMATION With kwin_x11 the second monitor works without problems. The Plasma version before 5.15.5 the problem was the same. If you say me how to debug Kwin to get more infos, I can do this. If there is some info utility about wayland multi monitor I can run it and post the infos. Here is the only info I have found per weston-info: interface: 'wl_output', version: 3, name: 30 x: 0, y: 0, scale: 1, physical_width: 310 mm, physical_height: 170 mm, make: 'N140HCA-EAB', model: 'eDP-1-unbekannt', subpixel_orientation: unknown, output_transform: normal, mode: width: 1920 px, height: 1080 px, refresh: 60.008 Hz, flags: current preferred This is the only wl_output section and belongs to the internal display. My secon d monitor is a Dell U2715H with 2560x1440. With GNOME Wayland the display is also recognized.
Does your notebook have multiple gpus?
No, the notebook has a single GPU: # lspci | grep -i vga 00:02.0 VGA compatible controller: Intel Corporation HD Graphics 620 (rev 02) # glxinfo name of display: :0 display: :0 screen: 0 direct rendering: Yes server glx vendor string: SGI server glx version string: 1.4 ... Extended renderer info (GLX_MESA_query_renderer): Vendor: Intel Open Source Technology Center (0x8086) Device: Mesa DRI Intel(R) HD Graphics 620 (Kaby Lake GT2) (0x5916) Version: 19.1.0 Accelerated: yes Video memory: 3072MB Unified memory: yes Preferred profile: core (0x1) Max core profile version: 4.5 Max compat profile version: 3.0 Max GLES1 profile version: 1.1 Max GLES[23] profile version: 3.2 I have updated to Plasma 5.16 and the problem remains the same.
I have the same problem. I run Arch Linux with kernel 5.9.13-arch1, kwin 5.20.4. I have Thinkpad P1 with Intel + Nvidia Quadro P2000 with nouveau drivers. However this works with Gnome! I see there two screens which on output of `xrandr` are labeled XWAYLAND0 and XWAYLAND1. At kde there is XWAYLAND0 only. Please tell me how can I get more info to debug it. As it works for me with Gnome out of the box I am sure I can help here :)
@Kamil Neczaj that sounds like you're experiencing bug 431062 - multi-GPU operation doesn't appear to work with Noveau for some reason. Please go there and provide the log, hopefully we can figure out what's going on. @ci3nte@gmail.com is it possible that your docking station is using DisplayLink? That would explain why it doesn't work in Plasma but does in GNOME - support for so-called "virtual GPUs" isn't implemented yet (and I know GNOME does support it).
Is this still an issue?
Reopen if the issue is still present