Orin series v4l2 cam0 port cannot be used

Issue Overview

The discussion centers around a problem encountered by developers using the Nvidia Jetson Orin Nano and Orin NX development kits while attempting to interface with a camera module through the V4L2 (Video for Linux 2) framework. Users report that they are unable to access data from the cam0 port, despite successful configurations in other frameworks like the Nvidia ISP (Image Signal Processor) framework.

Symptoms and Context

• Symptoms: Users are unable to retrieve data from the cam0 interface using V4L2, even after setting the lane_polarity parameter in the device tree. The command v4l2-ctl fails to fetch data, and no output is generated when trying to access the camera stream.

• Context: The issue arises when users attempt to configure camera settings directly through V4L2 while using Jetpack 5.1.2 and L4T 35.4.1 on official Nvidia development kits.

Hardware and Software Specifications

• Hardware: Nvidia Jetson Orin Nano and Orin NX development kits.

• Software: Jetpack 5.1.2 / L4T 35.4.1.

Frequency and Impact

• Frequency: The issue appears consistently among multiple users who have attempted similar configurations.

• Impact: This problem significantly hinders the ability to utilize the camera functionality on these development boards, affecting development timelines and project outcomes.

Possible Causes

• Hardware Incompatibilities or Defects: There may be issues related to specific camera models or compatibility with the Orin series hardware.

• Software Bugs or Conflicts: Potential bugs in the V4L2 implementation or conflicts between different software components may prevent proper camera access.

• Configuration Errors: Incorrect settings in the device tree or misconfigured parameters could lead to failures in accessing cam0.

• Driver Issues: Outdated or incorrect drivers may cause communication problems between the camera and the V4L2 framework.

• Environmental Factors: Power supply issues or thermal conditions could affect hardware performance.

• User Errors or Misconfigurations: Mistakes in setting up the device tree or using incorrect commands can lead to failures.

Troubleshooting Steps, Solutions & Fixes

Step-by-Step Instructions for Diagnosis

1. Verify Device Node Access:

   • Ensure you are accessing the correct video node. Use:

     ls /dev/video*
     

   • Check if /dev/video0 corresponds to your intended sensor ID.

2. Check Lane Polarity Configuration:

   • Confirm that lane_polarity is set correctly in your device tree.
   • Example configuration:

     lane_polarity = "6"; // Adjust as necessary
     

3. Inspect Sensor Pixel Clock Settings:

   • Review the pixel clock settings as incorrect configurations can lead to issues.
   • Refer to documentation related to sensor pixel clock parameters.

4. Use Debugging Tools:

   • Enable debugging logs for further insights:

     echo 1 > /sys/kernel/debug/tracing/tracing_on
     echo 30720 > /sys/kernel/debug/tracing/buffer_size_kb
     echo 1 > /sys/kernel/debug/tracing/events/tegra_rtcpu/enable
     echo 1 > /sys/kernel/debug/tracing/events/freertos/enable
     echo 2 > /sys/kernel/debug/camrtc/log-level
     echo 1 > /sys/kernel/debug/tracing/events/camera_common/enable
     echo > /sys/kernel/debug/tracing/trace
     

5. Test Different Configurations:

   • Experiment with different values for lane_polarity, such as:

     lane_polarity = "4"; // For testing purposes
     

6. Use Alternative Commands for Testing:

   • Try fetching data using v4l2-ctl with specific parameters:

     v4l2-ctl --set-fmt-video=width=1920,height=1080,pixelformat='RG10' --stream-mmap --stream-count=-1 --set-ctrl=sensor_mode=2 --set-ctrl=bypass_mode=0
     

7. Review Device Tree Settings:

   • Compare your device tree settings with those known to work on other Jetson devices (e.g., Jetson Nano, Xavier NX).

Recommended Solutions

• If you successfully receive data using nvarguscamerasrc, but not via V4L2, ensure that both methods are targeting the same video node.

• Consider updating your Jetpack version if you suspect software bugs or incompatibilities.

Best Practices for Future Prevention

• Regularly check for firmware updates and driver patches from Nvidia.

• Maintain a backup of working configurations for quick recovery during troubleshooting.

Unresolved Aspects

While several troubleshooting steps have been suggested, some users still report persistent issues with accessing cam0, indicating that further investigation may be needed into specific hardware compatibility or deeper software conflicts within the V4L2 framework.