Using a custom driver with Jetpack 6

Issue Overview

Users are experiencing difficulties when attempting to use a custom driver with the Nvidia Jetson Orin Nano Dev board, specifically related to the integration of the FDP Link III driver for the ds90ub954/ds90ub953. The main symptoms include:

• Inability to list the overlay after copying the .dtbo file into the appropriate directories.
• The error may stem from a Raspberry Pi-specific line in the .dtbo file, which is not compatible with the Orin Nano.
• Users have reported successfully compiling a kernel object (.ko) file and inserting it into the system but face challenges in getting it recognized at boot.

The issue arises during setup and configuration, particularly when trying to load device tree overlays. The hardware in question is the Jetson Orin Nano Devkit, and software specifications include Jetpack 6. The problem is consistent across multiple attempts, leading to frustration and hindering project progress.

Possible Causes

• Hardware incompatibilities or defects: The driver may be designed for a different hardware architecture (e.g., Jetson Nano instead of Orin Nano), leading to compatibility issues.

• Software bugs or conflicts: There may be bugs in the custom driver or conflicts with existing drivers on Jetpack 6 that prevent proper functionality.

• Configuration errors: Incorrect paths or configurations in the device tree overlay could lead to failure in recognizing the driver.

• Driver issues: The specific version of the driver may not be compatible with Jetpack 6 or may require modifications for proper integration.

• Environmental factors: Power supply issues or overheating could potentially affect performance, although this is less likely given the nature of the problem.

• User errors or misconfigurations: Users might inadvertently misconfigure settings or paths when trying to set up their environment.

Troubleshooting Steps, Solutions & Fixes

1. Verify Driver Compatibility:

   • Confirm that you are using a version of the driver compatible with Jetson Orin Nano. If necessary, consult with the vendor for an appropriate BSP (Board Support Package).

2. Check Device Tree Overlay Configuration:

   • Inspect the .dts and .dtbo files for any Raspberry Pi-specific configurations. Specifically, look for lines like:

     compatible = “brcm,bcm2835”
     

   • Remove or modify such lines as needed, but note that simply removing them did not resolve issues for some users.

3. Recompile and Insert Kernel Module:

   • Ensure that you have compiled the .ko file correctly. Use the following command to insert it:

     sudo cp ds90ub954.ko /lib/modules/$(uname -r)/kernel/drivers/media/i2c/
     sudo modprobe ds90ub954
     

4. Load Device Tree Overlay:

   • After copying the .dtbo file into /boot and /boot/dtb, verify that it is listed using:

     sudo /opt/nvidia/jetson-io/config-by-hardware.py -l
     

   • If it does not appear, double-check your paths and ensure that all necessary files are present.

5. Review Logs for Errors:

   • Check system logs for any error messages related to module loading or device tree overlays:

     dmesg | grep ds90ub954
     

6. Testing Different Configurations:

   • If possible, test with different versions of Jetpack or other hardware configurations to isolate whether the issue is specific to your current setup.

7. Consult Documentation and Community Forums:

   • Review Nvidia’s official documentation on device tree overlays and kernel modules for additional guidance.
   • Engage with community forums for insights from other users who may have faced similar issues.

8. Best Practices for Future Prevention:

   • Always ensure that drivers are up-to-date and compatible with your specific hardware model.
   • Maintain backups of working configurations before making changes.
   • Document any modifications made during troubleshooting for future reference.

If these steps do not resolve your issue, further investigation may be required, including reaching out to Nvidia support or exploring alternative drivers that are known to work with Jetson Orin Nano.