Display Port MST Hub support

Issue Overview

The discussion revolves around the use of the Multi-Stream Transport (MST) feature on the Nvidia Jetson Orin Nano Dev board, specifically regarding the integration of a DisplayPort (DP) hub IC, such as the LT8712SX. Users are experiencing uncertainty about whether they can replace a daisy-chain setup with a DP hub for their applications.

The symptoms include:

• Uncertainty in Hardware Compatibility: Users are unsure if the LT8712SX or similar MST hubs are supported by the Jetson Orin Nano.
• Potential Setup Issues: There may be challenges in configuring the MST feature correctly, leading to questions about optimal setups.

The problem occurs during the planning stage of using the Jetson Orin Nano for projects that require multiple displays. The hardware specifications include the Nvidia Jetson Orin Nano Dev board, which is designed for AI and machine learning applications but lacks explicit documentation on MST hub compatibility.

The frequency of this issue appears to be moderate, as multiple users have expressed similar concerns. The impact on user experience is significant, as it may hinder project development that relies on multi-display setups.

Possible Causes

Several potential causes could explain the users’ concerns regarding MST hub support:

• Hardware Incompatibilities: The Jetson Orin Nano may not support certain MST hubs due to design limitations or lack of driver support.

• Software Bugs or Conflicts: There could be unresolved software bugs in the Nvidia drivers that prevent proper communication with MST hubs.

• Configuration Errors: Users might not be configuring their systems correctly to utilize MST features, leading to confusion about functionality.

• Driver Issues: Outdated or incompatible drivers could lead to failures in establishing connections with MST hubs.

• User Errors or Misconfigurations: Lack of experience or understanding of how MST works could lead users to misconfigure their setups.

Troubleshooting Steps, Solutions & Fixes

To address the issues related to DisplayPort MST hub support on the Nvidia Jetson Orin Nano, follow these troubleshooting steps and potential solutions:

1. Verify Hardware Compatibility:

   • Check Nvidia’s official documentation or forums for any mention of supported MST hubs. If unavailable, consider reaching out to Nvidia support for clarification.

2. Update Drivers:

   • Ensure that all relevant drivers are up to date. Use the following command to check for updates:

     sudo apt update && sudo apt upgrade
     

3. Test Configuration:

   • If you are using a daisy-chain setup, document your current configuration settings.
   • Attempt to replicate your setup using just one display connected directly to the Jetson Orin Nano and gradually integrate additional displays through the MST hub.

4. Check Display Settings:

   • Use xrandr to check connected displays and their configurations:

     xrandr --listmonitors
     

   • Adjust settings as necessary based on what xrandr reports.

5. Isolate Issues:

   • Test with a different MST hub if possible, or try connecting displays directly without an MST hub to confirm that the Jetson Orin Nano functions correctly.

6. Community Engagement:

   • Engage with other users in forums or communities focusing on Nvidia products. Sharing experiences may yield insights or solutions that are not documented officially.

7. Documentation and Firmware Updates:

   • Regularly check for firmware updates related to your hardware components and apply them as necessary.

8. Best Practices:

   • Document your configurations and changes made during troubleshooting.
   • Keep backups of working configurations to quickly revert if new setups fail.

While no definitive solutions were highlighted in the forum discussion, engaging with other users and testing different configurations appears to be a recommended approach based on shared experiences. Further investigation into official Nvidia support channels may also provide clarity on compatibility issues with specific MST hubs like LT8712SX.