USB0 Device Mode Not Working on Custom Orin Nano Carrier Board

Issue Overview

The user is experiencing issues with a custom carrier board for the Nvidia Jetson Orin Nano. While the board successfully powers up and can be flashed in recovery mode, the USB0 port is not functioning correctly when the system boots normally. Specifically:

• USB0 is not detected by the host PC in normal boot mode
• The system cannot enter force recovery mode by holding FORCE_RECOVERY (pin 214) low
• Other USB ports (USB1 and USB2) on the carrier board are working correctly
• The user can log in via UART2 (debug) but cannot complete the SDK component installation due to USB0 issues

The problem occurs with a fresh Orin Nano (production module 4GB) and a blank NVMe SSD. The user successfully flashed the image to the NVMe, but cannot proceed with further setup steps due to the USB0 connectivity issue.

Possible Causes

1. Hardware design mismatch: Although the user claims to have followed the design guide, there might be subtle differences in the USB0 implementation compared to the devkit.

2. Device tree configuration: The custom carrier board may require changes to the device tree to properly support USB0 in normal boot mode.

3. USB role switch configuration: The system is not properly configuring the USB role switch for device mode operation.

4. Missing or incompatible USB controller: The custom carrier board may be missing a required USB controller (e.g., FUSB310) that is present on the devkit.

5. Software or driver issues: There could be problems with the USB device mode driver or related software components.

6. Power delivery or signal integrity issues: Although less likely, there could be power delivery or signal integrity problems affecting USB0 operation.

Troubleshooting Steps, Solutions & Fixes

1. Verify USB role switch configuration:
   Check the current USB role by running:

   cat /sys/class/usb_role/usb2-0-role-switch/role
   

   If it returns "none", the USB controller is not properly configured for device mode.

2. Update device tree for custom hardware:
   Since the custom carrier board is not using the FUSB310 controller present on the devkit, you’ll need to modify the device tree to match your hardware configuration. Create a custom device tree overlay that properly describes your USB0 implementation.

3. Check USB controller presence and configuration:
   Verify that your custom carrier board has the necessary USB controller for USB0 operation. If you’re not using the FUSB310, ensure that your alternative solution is properly integrated into the hardware design and software configuration.

4. Examine kernel logs for USB-related messages:
   Use dmesg or check /var/log/kern.log for any USB-related error messages or warnings. Pay particular attention to messages related to USB0 or the USB role switch.

5. Verify power and signal integrity:
   Double-check the power supply and signal routing for the USB0 interface. Ensure that all required power rails are present and within specification. Use an oscilloscope to verify signal integrity if possible.

6. Test with different USB cables and hosts:
   Try using different USB cables and host computers to rule out any cable or host-specific issues.

7. Update Jetson Linux and SDK:
   Ensure you are using the latest version of Jetson Linux and the NVIDIA SDK. Sometimes, software updates can resolve USB-related issues.

8. Modify USB port configuration:
   If the issue persists, you may need to modify the USB port configuration in the bootloader or kernel command line. Consult the Jetson Linux Developer Guide for information on customizing USB configurations.

9. Implement a workaround using other USB ports:
   If USB0 cannot be made to work in device mode, consider implementing a workaround using one of the working USB ports (USB1 or USB2) for development and debugging purposes.

10. Seek NVIDIA developer support:
    If the issue remains unresolved after trying these steps, consider reaching out to NVIDIA developer support or posting on the official Jetson developer forums for more specialized assistance.

Remember to document any changes made to the hardware or software configuration, as these will be important for future troubleshooting and development efforts.