Jetson Orin Nano > Display Port > DS90UH983 > Custom Display | Using Xorg to force EDID

Autonomous Machines Jetson & Embedded Systems Jetson Orin Nano
1

Hi there,

I’m attempting to connect a Nvidia Jetson Orin Nano (developer kit) to a DS90UH983-Q1EVM serialiser via a display port. The Serialiser connects to a custom display.

I have a script that sets the specific registers to enable the DS90UH983 to pass through the display port and I have edited the Xorg.conf file to use a custom EDID. The EDID seems to be working as when I plug in the Nvidia into a normal monitor, the GUI pops up with my custom resolutions.

The problem is:

  1. When running xrandr, the Nvidia isnt showing the DS90UH983-Q1EVM as being a connected display
  2. Nothing is being shown on the display
  3. The DS90UH983 script says the Video Processors are not syncing.

What are the best next steps? How can I debug this setup to locate where the issue is? Is the current method of using a custom EDID via Xorg enough to get the Nvidia to send a video stream through the DP? Or do I need to go into the device tree to create a driver or panel?

Side note: how would I enable DP MST, wondering as the DS90UH983 is expecting DP MST so not sure if that is the problem?

Any advice would be greatly appreciated.

Thank you!

Running Jetpack 6.1 | 5.15.148-tegra

3

Which jetpack release are you using?

When you hotplug the monitor, does xrandr or /var/log/Xorg.0.log gives out anything to tell you that there is a monitor connected?

4

Jetpack 36.4.0 - installed via SDK manager.

I viewed the Xorg.0.log and Xorg.1.log before and after hot plugging and there were no changes to the logs.

It seems most of the activity is occurring in Xorg.1.log. Below are the steps I took:

  1. Nvidia is ON and connected to a known DELL monitor. Confirmed that the resolution matches the EDID I am forcing
  2. Disconnected from monitor
  3. Xlog.0 and Xlog.1 viewed
  4. Displayport plugged into DS90UH983 DP port (aka custom screen).
  5. Xlog.0 and Xlog.1 viewed - no changes the hotplug occurred between 562.194 and 1515.545 time stamp on the Xlog.1.log
  6. Plugged back into known working DELL Monitor.

Please see attached for the logs:

Thank you kindly
Xorg.0.log (26.2 KB)
Xorg.1.log (25.3 KB)

5

If no log is printed for that hotplug , I think it is more like hardware signal issue that it cannot even trigger a plug event.

In brief, that device is not supported.

6

Therefore, would the best course of action be to delve into the DCB blob and add the device there? Or are you suggesting that even if that is added, the root problem is that there is no Hot plug detection signal from the monitor.

If there was HPD, would that be shown in the Xlog - what would it look like?

7

You could check how a hotplug event would be like in your xorg log by using a normal monitor first.

This issue has nothing to do with DCB bob. There is nothing related to this issue that could be added to DCB blob either… I totally have no idea what do you think you could add to DCB blob…