Unable to start SPI0 or 1 after Allied Imaging CSI Patch

Issue Overview

Users are experiencing difficulties with the SPI0 and SPI1 interfaces on the Nvidia Jetson Orin Nano Dev Board after applying a patch for Allied Vision’s CSI interface. The main symptoms include:

• Failure to initiate electrical output: Although the spidev modules (spidev0.0, 0.1, 2.0, 2.1) are present in /dev/ and can initiate transfers, there is no electrical activity observed.
• Loss of Jetson-IO functionality: After applying the patch using L4T-35.2.1-5.1.0, users report that the Jetson-IO tool is no longer available, complicating further configuration.
• Context of issue: This problem occurs post-patch installation while attempting to configure SPI interfaces for hardware communication.
• Hardware specifications: Users are working with the stock Orin Nano Dev Board and Jetpack version 5.1.3.
• Frequency of occurrence: The issue is consistently reproducible after the patch application.
• Impact on user experience: The inability to utilize SPI interfaces hinders development and integration with peripheral devices, significantly affecting functionality.

Possible Causes

Several potential causes could lead to the observed issues:

• Hardware incompatibilities or defects: The patch may not be compatible with the current hardware configuration, leading to failures in SPI functionality.
• Software bugs or conflicts: The applied patch might introduce bugs or conflicts with existing drivers or kernel modules.
• Configuration errors: Misconfigurations during the patching process could disable necessary functionalities.
• Driver issues: Missing or incorrect drivers for SPI interfaces could prevent proper operation.
• Environmental factors: Power supply inconsistencies might affect electrical outputs.
• User errors or misconfigurations: Incorrect settings in Jetson-IO prior to applying the patch could lead to these issues.

Troubleshooting Steps, Solutions & Fixes

To address the issue effectively, follow these comprehensive troubleshooting steps:

1. Verify Electrical Functionality:

   • Use a multimeter to confirm that SPI pins are receiving power and functioning as expected.

2. Revert to Stock Configuration:

   • Revert back to Jetpack 5.1.3 and use Jetson-IO to enable SPI interfaces again.
   • Collect dmesg logs for further analysis.

3. Recompile Device Tree Blob (DTB):

   • Extract the relevant sections from the original DTB file (before applying the patch) using:

     dtc -I dtb -O dts /path/to/original.dtb > /path/to/extracted.dts
     

   • Modify the extracted DTS file as needed and recompile it back into a DTB file using:

     dtc -I dts -O dtb /path/to/modified.dts > /path/to/new.dtb
     

4. Testing with spidev_test:

   • Run spidev_test to check if it can successfully initiate transfers:

     spidev_test -D /dev/spidev0.0
     

   • Check for any errors or lack of electrical activity using a protocol analyzer.

5. Inspect GPIOs:

   • Use memory addresses provided in forum discussions (e.g., 0x0243d008, 0x0243d018) to inspect GPIO configurations and verify their states.

6. Patch Documentation Review:

   • Review any documentation related to the CSI patch for compatibility notes or additional configuration steps that may have been overlooked.

7. Community Engagement:

   • Engage with community forums for advice on similar issues faced by other users, particularly those who resolved their problems successfully.

8. Firmware Updates:

   • Check for any firmware updates that may address known issues with SPI functionality post-patch.

9. Best Practices for Future Prevention:

   • Always back up current configurations before applying patches.
   • Test patches in a controlled environment before deploying them in production settings.

By following these steps, users can systematically diagnose and potentially resolve issues related to SPI functionality on their Nvidia Jetson Orin Nano Dev Board after applying specific patches.