Can't Extend Display with SM768 USB to HDMI on Jetson Nano

Robotics & Edge Computing Jetson & Embedded Systems Jetson Orin Nano
1

Hi,

I’m using a Jetson Nano with a Silicon Motion SM768 USB to HDMI adapter, trying to connect a second screen.

The SM768 device is detected correctly — it shows up in xrandr as DVI-I-1-1 and is marked as connected, with full EDID and available resolutions like 1920x1080@60Hz.
Also, I can confirm the screen works fine under a regular Ubuntu desktop (x86), and under Jetson Nano the kernel creates a valid /dev/dri/card2, so the EDID and DRM setup look valid.

Here’s a portion of my xrandr output:

DVI-I-1-1 connected 1920x1080  
   1920x1080     60.00 + 74.97 50.00 59.94  
   ... (other resolutions)

I also tried using the system’s display settings.
At first, the SM768 screen actually shows up — I can see two screens in the settings, and I can try choosing either “Mirror” or “Join Displays”.

The screen flashes a bit like it’s applying the change, but after a few seconds, it just goes back to the original setup with only the main screen active.
It feels like the system tries to use the SM768 screen, but then gives up and resets back.

When I try running this manually:

xrandr --setprovideroutputsource modesetting NVIDIA-0

It does nothing — no error, no extended desktop, and the second screen stays black.

Also, I don’t see any screen update or DPMS activity coming from the SM768 side, even though the monitor is connected.
It looks like the driver isn’t sending any display updates.

Here’s the result of xrandr --listproviders:

ubuntu@tegra-ubuntu:~$ xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x187 cap: 0x1, Source Output crtcs: 2 outputs: 2 associated providers: 1 name:NVIDIA-0  
Provider 1: id: 0x1e1 cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting

My questions:

  • Is this because the SM768 driver doesn’t support linking or sharing its display output with the main NVIDIA GPU on Jetson?
  • Is there any known workaround to make this work (like framebuffer copy)?
  • Has there been any update or workaround since this 2021 thread?

Environment:
Jetson Nano (JetPack 6.2)
Running on X11 session (not Wayland)

Would really appreciate any help or advice.

4

Sorry for the late response.
As this is related with external SM768 USB to HDMI device, we don’t have experience on it, may other developer help to provide suggestions.

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