Arch Linux

PurpleStephyr

Member

Registered: 2023-11-19

Posts: 5

[SOLVED] KDE Plasma - Monitor not drawing windows

I am seeing a weird issue where my external monitor is not drawing any windows. KDE display settings recognize it, but all that is there is a black screen. I can move the cursor over to the monitor, and the cursor becomes visible, but nothing else seems to display there. For example, if I drag a window over there, the cursor moves to the monitor, but the window itself does not display. My built-in laptop screen works as expected.

Edit: A few other things I've noticed:
- In SDDM, only the monitor seems to be used, the built-in laptop screen does not display anything, and cursor cannot move over to it at this time.
- If I unplug and re-plug the HDMI cable for the monitor, the monitor is no longer detected
- If I reboot the laptop with the HDMI cable unplugged, the monitor is not detected when plugging in the cable
- I have an extra device entry in KDE display settings called "Unknown-1". This does not seem to correspond to any device.

Edit2: inxi -Ga output:

inxi -Ga
Graphics:
  Device-1: Intel Raptor Lake-S UHD Graphics vendor: CLEVO/KAPOK driver: i915
    v: kernel alternate: xe arch: Gen-13 process: Intel 7 (10nm) built: 2022+
    ports: active: eDP-1 empty: DP-1, DP-2, HDMI-A-1, HDMI-A-2 bus-ID: 00:02.0
    chip-ID: 8086:a788 class-ID: 0300
  Device-2: NVIDIA AD107M [GeForce RTX 4060 Max-Q / Mobile]
    vendor: CLEVO/KAPOK driver: nvidia v: 560.35.03
    alternate: nouveau,nvidia_drm non-free: 550.xx+
    status: current (as of 2024-06) arch: Lovelace code: AD1xx
    process: TSMC n4 (5nm) built: 2022+ pcie: gen: 1 speed: 2.5 GT/s lanes: 8
    link-max: gen: 4 speed: 16 GT/s ports: active: none off: HDMI-A-3
    empty: DP-3,DP-4,eDP-2 bus-ID: 01:00.0 chip-ID: 10de:28e0 class-ID: 0300
  Device-3: Bison BisonCam NB Pro driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-8:5 chip-ID: 5986:214c
    class-ID: 0e02 serial: 01.00.00
  Display: wayland server: X.org v: 1.21.1.13 with: Xwayland v: 24.1.2
    compositor: kwin_wayland driver: X: loaded: modesetting failed: nvidia
    alternate: fbdev,intel,nouveau,nv,vesa dri: iris gpu: i915,nvidia
    d-rect: 3600x2130 display-ID: 0
  Monitor-1: HDMI-A-3 pos: bottom-l res: 1680x1050 size: N/A modes: N/A
  Monitor-2: eDP-1 pos: top-right res: 1920x1080 size: N/A modes: N/A
  API: EGL v: 1.5 hw: drv: intel iris drv: nvidia platforms: device: 0
    drv: nvidia device: 1 drv: iris device: 3 drv: swrast gbm: drv: iris
    surfaceless: drv: nvidia wayland: drv: swrast x11: drv: swrast
    inactive: device-2
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: mesa v: 24.2.1-arch1.1
    glx-v: 1.4 direct-render: yes renderer: llvmpipe (LLVM 18.1.8 256 bits)
    device-ID: ffffffff:ffffffff memory: 30.46 GiB unified: yes
    display-ID: :1.0
  API: Vulkan v: 1.3.279 layers: 5 device: 0 type: discrete-gpu name: NVIDIA
    GeForce RTX 4060 Laptop GPU driver: nvidia v: 560.35.03
    device-ID: 10de:28e0 surfaces: xcb,xlib,wayland

Edit3: This seems to be specific to wayland, it is working as expected with X11.

Edit4: Solved the issue, had to set nvidia_drm.fbdev parameter as well:

sudo modprobe nvidia_drm fbdev=1

cat /etc/modprobe.d/nvidia_drm.conf  
options nvidia_drm modeset=1
options nvidia_drm fbdev=1

Last edited by PurpleStephyr (2024-08-30 23:42:56)

seth

Member

Registered: 2012-09-03

Posts: 60,787

Re: [SOLVED] KDE Plasma - Monitor not drawing windows

- I have an extra device entry in KDE display settings called "Unknown-1". This does not seem to correspond to any device.

That's the simpledrm device,  please post your Xorg log, https://wiki.archlinux.org/title/Xorg#General

Edit: yeah, an F5 might have been a good idea…
Enable https://wiki.archlinux.org/title/NVIDIA … de_setting - use the "nvidia_drm.modeset=1" kernel parameter (modprobe.conf won't do!) to get rid of the simpledrm device and modesetting is also required to use the nvidia GPU (where the output is likely wired) w/ wayland.
If that doesn't solve it, post the output of "kscreen-doctor" and/or "qdbus6 org.kde.KWin /KWin supportInformation"

Last edited by seth (2024-08-30 22:08:44)

---

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

PurpleStephyr

Member

Registered: 2023-11-19

Posts: 5

Re: [SOLVED] KDE Plasma - Monitor not drawing windows

Xorg logs (although I suspect they won't be useful since I'm using wayland): https://termbin.com/4ea8

I already had nvidia_drm.modeset=1 set:

sudo cat /sys/module/nvidia_drm/parameters/modeset
Y

kscreen-doctor -o output:

kscreen-doctor -o    
Output: 1 Unknown-1
        disabled
        connected
        priority 0
        Unknown
        Modes:  0:800x600@60*! 
        Geometry: -800,240 800x600
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: incapable
        RgbRange: unknown
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none
        Color profile source: sRGB
Output: 2 HDMI-A-3
        enabled
        connected
        priority 2
        HDMI
        Modes:  0:1680x1050@60*!  1:1680x1050@60  10:800x600@72  11:800x600@60  12:800x600@56  13:640x480@75  14:640x480@73  15:640x480@60  2:1280x1024@75  3:1280x1024@60  4:1280x960@60  5:1152x864@75  6:1024x768@75  7:1024x768@70  8:1024x768@60  9:800x600@75 
        Geometry: 0,15 1680x1050
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: incapable
        RgbRange: unknown
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none
        Color profile source: EDID
Output: 3 eDP-1
        enabled
        connected
        priority 1
        Panel
        Modes:  0:1920x1080@165*!  1:1280x1024@60  2:1024x768@60  3:1280x800@60  4:1920x1080@60  5:1600x900@60  6:1368x768@60  7:1280x720@60 
        Geometry: 1680,0 1920x1080
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: Automatic
        RgbRange: Automatic
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none
        Color profile source: EDID

Output: 2 HDMI-A-3 is the problematic device.

KWin support information: https://termbin.com/pj8d

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,880

Re: [SOLVED] KDE Plasma - Monitor not drawing windows

Make sure you actually set that parameter on the kernel cmdline not via a modprobe config option. It needs to be on the cmdline to trigger the logic to disable the simpledrm device.

Right now KWin runs on a software renderer which is never what you want.

PurpleStephyr

Member

Registered: 2023-11-19

Posts: 5

Re: [SOLVED] KDE Plasma - Monitor not drawing windows

I had to set nvidia_drm.fbdev parameter as well. Looks like it is working now. Thanks!

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,880

Re: [SOLVED] KDE Plasma - Monitor not drawing windows

Yes that's the other way of avoiding it, but as mentioned had you used the cmdline method you could've avoided the fbdev (which used to have issues - which is why we hesitate to immediately reccommend it -- but maybe that has changed)