No display found with ddcutil on Jetson Orin Nano

Issue Overview

Users are experiencing issues with the Nvidia Jetson Orin Nano Dev board when attempting to use the ddcutil command to control their HDMI monitor. The specific symptom reported is the error message "No display found" when executing the command ddcutil detect -verbose.

This issue arises during the setup phase when users are trying to detect and control their displays. Users have confirmed that their monitors support DDC control and have successfully used ddcutil on other Linux desktops, indicating that the problem is specific to the Jetson Orin Nano.

The hardware setup includes a passive DisplayPort (DP) to HDMI adapter connecting to an HDMI monitor. Some users speculate whether switching to an active DP to HDMI adapter might resolve the issue. The frequency of this problem appears consistent among users attempting similar setups, significantly impacting their ability to control monitor settings programmatically.

Possible Causes

• Hardware Incompatibilities: The integrated GPU (iGPU) on the Jetson may not fully support DDC queries as discrete GPUs (dGPUs) do, leading to compatibility issues with tools like ddcutil.

• Software Bugs or Conflicts: There may be bugs in the drivers or conflicts between different software components that prevent proper communication with the display.

• Configuration Errors: Incorrect configurations related to display settings or driver installations could hinder functionality.

• Driver Issues: The drivers for the iGPU may not support DDC commands in the same way as those for a dGPU, limiting functionality.

• Environmental Factors: While less likely, factors such as power supply issues or temperature could potentially affect performance.

• User Errors or Misconfigurations: Users may inadvertently misconfigure their systems or overlook necessary steps in setup.

Troubleshooting Steps, Solutions & Fixes

1. Verify Hardware Compatibility:

   • Ensure that your monitor supports DDC control.
   • Check if using a passive DP to HDMI adapter is appropriate; consider switching to an active DP to HDMI adapter if issues persist.

2. Check EDID Information:

   • Run the following command to locate EDID files:

     find /sys -name 'edid'
     

   • For each file found, navigate to its location and execute:

     cat edid
     

   • This will display EDID content directly from the driver, which may provide insights into display recognition issues.

3. Test Different Display Modes:

   • Use xrandr to switch between available modes. Note that xrandr can only switch to modes defined in the EDID.

4. Driver Updates:

   • Ensure that you have the latest drivers installed for your Jetson device. Check Nvidia’s official site for any updates or patches related to your issue.

5. Isolation Testing:

   • Test with different hardware configurations (e.g., different monitors or cables) to isolate whether the issue lies with specific components.

6. Consult Documentation:

   • Review Nvidia’s documentation on Jetson Orin Nano for any notes regarding display support and DDC functionality.

7. Community Support:

   • Engage with community forums or Nvidia’s support channels for additional insights or similar experiences from other users.

8. Best Practices:

   • Regularly update your system and monitor configurations.
   • Document any changes made during troubleshooting for future reference.

Note on Unresolved Aspects

While various users have noted potential issues with using ddcutil due to the iGPU architecture of the Jetson Orin Nano, further investigation may be necessary regarding driver capabilities and compatibility with DDC commands.