No signal on external monitor with the docking station

English Hardware
1

Hello everyone. I’ve bought WAVLINK WL-UMD03 docking station and connected it to the USB-C port on my 7-years old DELL Latitude 5490. This port is described by Dell’s manual as a “DisplayPort over USB-C”. The power delivery as well as other USB devices worked fine over the docking station but there is no signal on my external monitor which is connected to the docking station via a HDMI cable. I could see this in the journal when connecting the HDMI cable into the docking station:

sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: failed to open drm device at ""
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::DrmOutput(0x56527fea7e00, name="DP-2", geometry=QRect(0,0 1920x1200>
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: failed to open drm device at ""
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: failed to open drm device at ""
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:45 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:47:46 localhost.localdomain xdg-desktop-portal-kde[3356]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain ksecretd[2991]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain kded6[3198]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_migration_agent[3922]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain DiscoverNotifier[3501]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain plasmashell[3321]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain plasmashell[3321]: kde.plasmashell: requesting unexisting screen available rect -1
sep 21 21:47:46 localhost.localdomain kwalletd6[3303]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain kactivitymanagerd[3348]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain polkit-kde-authentication-agent-1[3353]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain baloorunner[4298]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain krunner[4243]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_mailmerge_agent[3919]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_newmailnotifier_agent[3927]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain yakuake[3491]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_followupreminder_agent[3905]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_sendlater_agent[3928]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain kalendarac[3503]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_maildispatcher_agent[3914]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_archivemail_agent[3892]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_control[3701]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_mailfilter_agent[3917]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain akonadi_unifiedmailbox_agent[3929]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain kwin_wayland[3052]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::DrmOutput(0x56527fea7e00, name="DP-2", geometry=QRect(0,0 1920x1200>
sep 21 21:47:46 localhost.localdomain kwin_wayland[3052]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::DrmOutput(0x56527fea7e00, name="DP-2", geometry=QRect(0,0 1920x1200>
sep 21 21:47:46 localhost.localdomain kwin_wayland_wrapper[3154]: XWAYLAND: mode -1x-1 is not available
sep 21 21:47:46 localhost.localdomain kwin_wayland_wrapper[3154]: XWAYLAND: mode -1x-1 is not available
sep 21 21:47:46 localhost.localdomain kwin_wayland_wrapper[3154]: XWAYLAND: mode -1x-1 is not available
sep 21 21:47:46 localhost.localdomain org_kde_powerdevil[3354]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:47:46 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Adding connected display with bus 8
sep 21 21:47:46 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: atomic commit failed: Invalid argument
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: atomic commit failed: No free space on the device
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Emitting DDCA_Display_Status_Event[13357.668:  DDCA_EVENT_DISPLAY_CONNECTED, card1-DP-2, dref: DDCA_Display_Ref[18], io_path:/dev/i2c-8,>
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Starting 1 callback threads
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] libddcutil callback thread 0x7f51a400f3c0 started
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Started 1 event callback thread(s)
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 11488] Invoking callback function 0x7f51ce3828e0 for event DDCA_Display_Status_Event[13357.668:  DDCA_EVENT_DISPLAY_CONNECTED, card1-DP-2, dref>
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Starting 1 callback threads
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] libddcutil callback thread 0x7f51a400f3c0 started
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10949] Started 1 event callback thread(s)
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 11488] Invoking callback function 0x7f51ce3828e0 for event DDCA_Display_Status_Event[13357.668:  DDCA_EVENT_DISPLAY_CONNECTED, card1-DP-2, dref>
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 11488] Callback function 0x7f51ce3828e0 for event DDCA_Display_Status_Event[13357.668:  DDCA_EVENT_DISPLAY_CONNECTED, card1-DP-2, dref: DDCA_Di>
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Quiescing libddcutil API...
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Quiesce libddcutil API complete
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Display redetection starting.
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [ 10948] recheck thread terminating because watch thread terminated
sep 21 21:47:47 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Watch thread terminated.
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: atomic commit failed: No free space on the device
sep 21 21:47:47 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:48 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:48 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Bad link status detected on connector DP-2
sep 21 21:47:48 localhost.localdomain kernel: i915 0000:00:02.0: [drm] *ERROR* [CONNECTOR:123:DP-1][ENCODER:122:DDI C/PHY C][DPRX] Can't reduce link training parameters after failure
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Watching for display connection changes, resolved watch mode = Watch_Mode_Xevent, poll loop interval = 100 millisec
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354]                                          extra_stabilization_millisec: 0,  stabilization_poll_millisec: 100
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354] libddcutil recheck thread 0x55ade5cb89c0 started
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [ 11493] (dw_recheck_displays_func) Recheck interval: Sleeping for 200 milliseconds
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354] libddcutil watch thread 0x55ade5cd5110 started
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Display redetection finished.
sep 21 21:47:48 localhost.localdomain org_kde_powerdevil[3354]: [  3354] Unquiescing libddcutil API...
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::DrmOutput(0x56527e454170, name="eDP-1", geometry=QRect(0,0 1920x108>
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:15 localhost.localdomain kwin_wayland[3052]: kwin_wayland_drm: Atomic modeset test failed! Invalid argument
sep 21 21:49:16 localhost.localdomain kwalletd6[3303]: qt.qpa.wayland: There are no outputs - creating placeholder screen
sep 21 21:49:16 localhost.localdomain kactivitymanagerd[3348]: qt.qpa.wayland: There are no outputs - creating placeholder screen

inxi output while the HDMI cable is connected to the docking station:

inxi -GSaz
System:
  Kernel: 6.16.7-1-default arch: x86_64 bits: 64 compiler: gcc v: 15.2.0 clocksource: tsc
    avail: acpi_pm parameters: BOOT_IMAGE=/boot/vmlinuz-6.16.7-1-default
    root=UUID=5990d399-97de-4fd0-a430-6a1e717fcd20 splash=silent quiet security=apparmor
    mitigations=auto
  Console: pty pts/1 DM: SDDM Distro: openSUSE Tumbleweed 20250919
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel arch: Gen-9.5
    process: Intel 14nm built: 2016-20 ports: active: DP-2 off: eDP-1 empty: DP-1, DP-3, DP-4,
    HDMI-A-1, HDMI-A-2 bus-ID: 00:02.0 chip-ID: 8086:5917 class-ID: 0300
  Device-2: Sunplus Innovation Integrated_Webcam_HD driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-5:3 chip-ID: 1bcf:2b96 class-ID: 0e02
  Display: unspecified server: X.org v: 1.21.1.15 with: Xwayland v: 24.1.8
    compositor: kwin_wayland driver: X: loaded: modesetting unloaded: vesa alternate: fbdev,intel
    dri: iris gpu: i915 tty: 210x65
  Monitor-1: DP-2 model: Dell U2415 serial: <filter> built: 2014 res: 1920x1200 dpi: 94
    gamma: 1.2 size: 518x324mm (20.39x12.76") diag: 611mm (24.1") ratio: 16:10 modes: max: 1024x768
    min: 720x400
  Monitor-2: eDP-1 model: ChiMei InnoLux 0x14c9 built: 2017 res: 1920x1080 dpi: 158 gamma: 1.2
    size: 309x173mm (12.17x6.81") diag: 354mm (13.9") ratio: 16:9 modes: 1920x1080
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris device: 1 drv: swrast gbm:
    drv: iris surfaceless: drv: iris inactive: wayland,x11
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: mesa v: 25.2.2 note: console (EGL sourced)
    renderer: Mesa Intel UHD Graphics 620 (KBL GT2), llvmpipe (LLVM 21.1.0 256 bits)
  API: Vulkan v: 1.4.321 layers: 1 device: 0 type: integrated-gpu name: Intel UHD Graphics 620
    (KBL GT2) driver: mesa intel v: 25.2.2 device-ID: 8086:5917 surfaces: N/A device: 1 type: cpu
    name: llvmpipe (LLVM 21.1.0 256 bits) driver: mesa llvmpipe v: 25.2.2 (LLVM 21.1.0)
    device-ID: 10005:0000 surfaces: N/A
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo de: kscreen-console,kscreen-doctor
    wl: wayland-info x11: xdpyinfo, xprop, xrandr

inxi output while the external monitor is connected directly to the laptop via HDMI:

inxi -GSaz
System:
  Kernel: 6.16.7-1-default arch: x86_64 bits: 64 compiler: gcc v: 15.2.0 clocksource: tsc
    avail: acpi_pm parameters: BOOT_IMAGE=/boot/vmlinuz-6.16.7-1-default
    root=UUID=5990d399-97de-4fd0-a430-6a1e717fcd20 splash=silent quiet security=apparmor
    mitigations=auto
  Console: pty pts/1 DM: SDDM Distro: openSUSE Tumbleweed 20250919
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel arch: Gen-9.5
    process: Intel 14nm built: 2016-20 ports: active: HDMI-A-1 off: eDP-1 empty: DP-1,HDMI-A-2
    bus-ID: 00:02.0 chip-ID: 8086:5917 class-ID: 0300
  Device-2: Sunplus Innovation Integrated_Webcam_HD driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-5:3 chip-ID: 1bcf:2b96 class-ID: 0e02
  Display: unspecified server: X.org v: 1.21.1.15 with: Xwayland v: 24.1.8
    compositor: kwin_wayland driver: X: loaded: modesetting unloaded: vesa alternate: fbdev,intel
    dri: iris gpu: i915 tty: 210x65
  Monitor-1: HDMI-A-1 model: Dell U2415 serial: <filter> built: 2014 res: 1920x1200 dpi: 94
    gamma: 1.2 size: 518x324mm (20.39x12.76") diag: 611mm (24.1") ratio: 16:10 modes: max: 1920x1200
    min: 720x400
  Monitor-2: eDP-1 model: ChiMei InnoLux 0x14c9 built: 2017 res: 1920x1080 dpi: 158 gamma: 1.2
    size: 309x173mm (12.17x6.81") diag: 354mm (13.9") ratio: 16:9 modes: 1920x1080
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris device: 1 drv: swrast gbm:
    drv: iris surfaceless: drv: iris inactive: wayland,x11
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: mesa v: 25.2.2 note: console (EGL sourced)
    renderer: Mesa Intel UHD Graphics 620 (KBL GT2), llvmpipe (LLVM 21.1.0 256 bits)
  API: Vulkan v: 1.4.321 layers: 1 device: 0 type: integrated-gpu name: Intel UHD Graphics 620
    (KBL GT2) driver: mesa intel v: 25.2.2 device-ID: 8086:5917 surfaces: N/A device: 1 type: cpu
    name: llvmpipe (LLVM 21.1.0 256 bits) driver: mesa llvmpipe v: 25.2.2 (LLVM 21.1.0)
    device-ID: 10005:0000 surfaces: N/A
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo de: kscreen-console,kscreen-doctor
    wl: wayland-info x11: xdpyinfo, xprop, xrandr

I have tried to search for some of the above messages but either found posts associated with NVIDIA (I only have Intel iGPU) or they were related to KDE 5.

I have tested the docking station with Windows 11 on my (much newer) work laptop and the output to the external monitor worked fine.

Do you have any suggestion on which error message / check I should focus on?

2

Check to see if the laptop has a firmware update available.

IIUC, what makes a USB-C-connected dock work is DisplayPort’s MST functionality that is not available from HDMI. DisplayPort outputs can be converted easily to HDMI imputs, but not vice versa. So if there is no firmware update to try, and the Dell has a DP input, try connecting dock to it via DP to DP cable, or at least try using the dock’s DP output with adapter or cable with one end HDMI.

I have a similar GPU, so probably a similar CPU, and found kernel command line parameter i915.enable_guc=2 fixed or helped something, but so long ago I can’t remember details. The archlinux wiki explains it’s about firmware loading.

1 Like
3

Thank you for the recommendations. Although none of them fixed the issue, MST thing made me read something more about the display port. I found the display port specification on my laptop, it should be display port 1.2 over usb-c. Based on wiki, MST was introduced with display port 1.2 so I should be fine even with DP over usb-c → docking station → HDMI.

I have tested several combinations:

  1. my dell laptop with Tumbleweed → DP over usb-c → my WAVLINK docking station → DP-DP cable (instead of HDMI) → external monitor => no signal
  2. my dell laptop booted into Fedora Workstation LIVE → DP over usb-c → my WAVLINK docking station → DP-DP cable → external monitor => no signal
  3. two different laptops with Win 11 → DP over usb-c → my WAVLINK docking station → DP-DP cable → external monitor => it worked fine
  4. my dell laptop with Tumbleweed → DP over usb-c → docking station at work (HP dock G5) → DP-DP cable → external monitor => it worked fine

and also two other things you mentioned:
a) laptop BIOS updated to the latest version => it didn’t help
b) laptop started i915.enable_guc=2 => no signal

Btw, when I connect the laptop to the WAVELINK docking station, I can see the external monitor in the Display settings in KDE, but the maximum resolution I can set is only 1024x768 and the external monitor says “no signal”.

As it neither works with Fedora on Gnome, I suspect it is more a HW compatibility thing. The issue is always associated with the following message in the journal:

kwin_wayland_drm: Bad link status detected on connector DP-2

Nevertheless, I bought this WAVLINK docking station primarily for my new laptop which should arrive in a few days. If it works fine with the new laptop, I am fine :slight_smile:

4

It may be while you wait (with nothing to do :stuck_out_tongue: ) you could try implementing a custom EDID file for loading via kernel command line as a workaround to light up the external with doc and old laptop, so that it can remain a fully functional backup after the new arrives. It’s not something I’ve ever done, but I’ve seen discussions about it more than a few times on the WWW, such as here.

Have you tried connecting the dock to a TV or some other monitor instead of your customary external monitor, to see if your external is where the shortcoming lies?

5

The external monitor works fine over the docking station with the new laptop so I consider this topic as closed. If I still use the old laptop, I can connect it directly to the external monitor. Thank you for your support and all the recommendations!

1 Like
6

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