Dual monitor over USB-C only mirror

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1

I have fresh installation of Fedora 41 with gnome on a laptop. Having two external monitors. These are both connected via display port using one adapter, connected to laptop via USB-C.

Monitors are working, but only as a mirror - There is a same feed to both of the. System’s Displays utility only show one external monitor - so no way to easily split the view.

I tried the same adapter on two other laptops (f40 and kubuntu 24.04), worked completely fine as 2 separate external monitors on it, so I it is not a faulty adapter.

System is running wayland. I tried to check displays via xrandr -q and it only detected build-in display + one external monitor:

$: xrandr -q
creen 0: minimum 16 x 16, current 3840 x 1200, maximum 32767 x 32767
eDP-1 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 340mm x 220mm
   1920x1200     59.88*+
...
DP-2 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 530mm x 300mm
   1920x1080     59.96*+
   1440x1080     59.99  
   1400x1050     59.98 
...

What can I do to fix this?

2

Are all 3 laptops the same make/model with same vendor firmware updates? Laptops use an array of configurations to deal with multiple displays: if they are not the same compare the hardware details (use inxi) and vendor specs to determine how they handle external displays. Then compare the modules related to displays that are loaded on systems with the displays working with the system that is not working.

If the laptops are identical, you are looking for differences in the names and versions of modules that are loaded. Look for relevant errors using journalctl “filters”.

3

Laptops are not the same model. All 3 are lenovo, but the non-working one in ThinkPad L16 Gen 1 (16, AMD) with graphic card - AMD Radeon™ 780M. The working ones are T14s with Intel graphics.

Kernel version on non-working one is 6.11.7

Output of inxi -Gxxx:

  Device-1: Advanced Micro Devices [AMD/ATI] Phoenix1 vendor: Lenovo
    driver: amdgpu v: kernel arch: RDNA-3 pcie: speed: 16 GT/s lanes: 16 ports:
    active: DP-2,eDP-1 empty: DP-1, DP-3, DP-4, DP-5, DP-6, HDMI-A-1,
    Writeback-1 bus-ID: c4:00.0 chip-ID: 1002:15bf class-ID: 0300 temp: 29.0 C
  Device-2: Bison Integrated Camera driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 bus-ID: 3-1:2 chip-ID: 5986:118c class-ID: fe01
    serial: 200901010001
  Display: wayland server: Xwayland v: 24.1.4 compositor: gnome-shell
    v: 47.1 driver: gpu: amdgpu display-ID: 0
  Monitor-1: DP-2 model: Philips PHL 242B1 serial: UHB2324006878
    res: 1920x1080 dpi: 93 size: 527x296mm (20.75x11.65") diag: 604mm (23.8")
    modes: max: 1920x1080 min: 720x400
  Monitor-2: eDP-1 model-id: CSO 0x160d res: 1920x1200 dpi: 142
    size: 344x215mm (13.54x8.46") diag: 406mm (16") modes: max: 1920x1200
    min: 640x480
  API: OpenGL v: 4.6 vendor: amd mesa v: 24.2.6 glx-v: 1.4 es-v: 3.2
    direct-render: yes renderer: AMD Radeon 780M (radeonsi gfx1103_r1 LLVM
    19.1.0 DRM 3.59 6.11.6-300.fc41.x86_64) device-ID: 1002:15bf
    display-ID: :0.0
  API: EGL Message: EGL data requires eglinfo. Check --recommends.

Not sure what “modules” should I look for.

4

What are the specs of the “adapter”? Are any of the systems using the 3rd party DIsplayLink software (with EVDI)?

It is unlikely that this issue is specific to Fedora, so searching for you issue across other forums may find other reports and possibly a solution.

5

Adapter is this one - https://www.alza.cz/EN/i-tec-usb-c-dual-displayport-d5127952.htm?setlang=en-GB
AFAIK no 3rd party DisplayLink SW is used on any of these laptops.

I will try to run some other live distro and see if issues persist.

6

I tried to run kubuntu 24.10 on same laptop and experienced the same issue. So this issue is definitely not specific to Fedora.