Image Desynchronization Issue in DOL2 Mode

Issue Overview

Users are experiencing an image desynchronization issue while debugging DOL2 simulations on the Nvidia Jetson Orin Nano Dev board. The symptoms include improper synchronization of images, leading to noticeable image splitting during operation. This problem arises specifically in DOL2 mode, as indicated by user reports.

The setup involves the Jetson Orin Nano running software version R35.4.1, and users have attempted to adjust various parameters in the device tree source (DTS) file, including increasing the pixel clock frequency (pix_clk_hz) from 288000000 to 600000000, which only slightly mitigated the splitting issue. Other parameters such as active_h and num_of_lines_offset_0 were also modified without success. The issue persists despite successful tests of the sensor configuration on other platforms, indicating that it may be specific to the Jetson environment.

The impact of this issue is significant, as it hampers the functionality of applications relying on synchronized image capture, thereby affecting user experience and potentially leading to incorrect data processing.

Possible Causes

1. Hardware Incompatibilities or Defects:

   • The issue may stem from incompatibilities between the Jetson Orin Nano and the IMX662 sensor being used.

2. Software Bugs or Conflicts:

   • Bugs in the driver or firmware specific to DOL2 mode might lead to synchronization errors.

3. Configuration Errors:

   • Incorrect settings in the device tree source file may cause improper image handling.

4. Driver Issues:

   • Outdated or incompatible drivers for the camera sensor could contribute to desynchronization.

5. Environmental Factors:

   • Power supply inconsistencies or thermal issues might affect performance.

6. User Errors or Misconfigurations:

   • Misconfigured settings in the camera initialization process could lead to synchronization problems.

Troubleshooting Steps, Solutions & Fixes

1. Diagnosing the Problem:

   • Verify that all hardware connections are secure and properly configured.
   • Check for any visible error messages in system logs related to camera initialization or operation.

2. Gathering System Information:

   • Use commands to check camera device status:

     v4l2-ctl --list-devices
     

   • Review logs for any anomalies during image capture:

     dmesg | grep -i camera
     

3. Isolating the Issue:

   • Test with different clock rates by executing:

     echo 1 > /sys/kernel/debug/bpmp/debug/clk/vi/mrq_rate_locked
     echo 1 > /sys/kernel/debug/bpmp/debug/clk/isp/mrq_rate_locked
     echo 1 > /sys/kernel/debug/bpmp/debug/clk/nvcsi/mrq_rate_locked
     

   • Experiment with changing active_h and num_of_lines_offset_0 values in the DTS file and observe any changes in behavior.

4. Potential Fixes or Workarounds:

   • If SDR mode operates normally, consider using it as a temporary solution until DOL2 issues are resolved.
   • Revert to a previously stable driver version if recent updates are suspected to introduce bugs.

5. Documentation and Updates:

   • Ensure that you are using the latest firmware and drivers from NVIDIA’s official site.
   • Review relevant documentation for any updates regarding DOL2 mode support.

6. Best Practices for Prevention:

   • Regularly check for software updates and patches from NVIDIA.
   • Maintain a backup of stable configurations before making significant changes to settings.

7. Unresolved Aspects:

   • Further investigation may be needed regarding specific register configurations for the IMX662 sensor that could affect DOL2 operation.
   • Users should monitor NVIDIA forums for any emerging solutions or shared experiences related to this issue.

By following these steps, users can systematically address the image desynchronization problem encountered while using the Nvidia Jetson Orin Nano Dev board in DOL2 mode.