Kernel Panic During PCIe Communication Between x86 and Jetson Orin Nano

Issue Overview

Users are experiencing a kernel panic when attempting to establish PCIe communication between an x86 board and a Jetson Orin Nano. The issue occurs specifically when running iperf3 to stress test the PCIe communication. The problem manifests after running iperf3 for a short period, resulting in a kernel panic on the Jetson Orin Nano. The issue appears to be consistent and reproducible.

Key details:

• Hardware: NVIDIA Orin Nano Developer Kit
• JetPack version: 5.1.3
• Communication method: PCIe with tegra_vnet.ko driver
• Test command: iperf3 -u -c 192.168.193.5 -b 2000M -t 999

Possible Causes

1. Incompatible driver: The tegra_vnet driver may not be designed for x86 to Jetson communication, as it’s meant for Jetson-to-Jetson connections.

2. Driver bug: There could be a bug in the tegra_vnet driver causing issues under high-stress conditions.

3. Hardware limitation: The Jetson Orin Nano might have limitations in handling high-bandwidth PCIe communication with x86 systems.

4. Software conflict: JetPack 5.1.3 or the kernel version might have compatibility issues with the PCIe communication setup.

5. Resource exhaustion: The high data transfer rate might be causing resource exhaustion, leading to the kernel panic.

Troubleshooting Steps, Solutions & Fixes

1. Verify driver compatibility:

   • Confirm that the tegra_vnet driver is designed for x86 to Jetson communication.
   • Check NVIDIA’s official documentation for supported PCIe communication methods between x86 and Jetson platforms.

2. Update software:

   • Ensure you’re using the latest JetPack version and all available updates are installed.
   • Check for any available updates to the tegra_vnet driver.

3. Adjust iperf3 parameters:

   • Try reducing the bandwidth in the iperf3 command to see if the issue persists at lower data rates.
   • Example: iperf3 -u -c 192.168.193.5 -b 1000M -t 999

4. Monitor system resources:

   • Use tools like top, htop, or nvidia-smi to monitor CPU, memory, and GPU usage during the iperf3 test.
   • Look for any resource bottlenecks or unusual spikes in usage.

5. Check kernel logs:

   • Examine /var/log/syslog or use dmesg to look for any relevant error messages or warnings before the kernel panic occurs.

6. Test with different PCIe communication methods:

   • Investigate alternative PCIe communication methods supported by NVIDIA for x86 to Jetson connections.
   • Consider using memory mapping communication if available.

7. Contact NVIDIA support:

   • If the issue persists, reach out to NVIDIA developer support for guidance on supported PCIe communication methods between x86 and Jetson platforms.

8. Implement error handling in your application:

   • Add robust error handling and recovery mechanisms in your application to gracefully handle communication failures.

9. Consider alternative communication methods:

   • If PCIe communication proves unreliable, explore other communication protocols like Ethernet or USB that might be more stable for your use case.

10. Kernel parameter tuning:

    • Investigate kernel parameters related to PCIe and network stack performance.
    • Consult NVIDIA documentation for recommended kernel parameter settings for high-performance PCIe communication.

11. Debug with lower-level tools:

    • Use PCIe debugging tools like lspci and setpci to examine the PCIe configuration and status.
    • Example commands:

      lspci -vvv
      setpci -s <PCIe device> <register>=<value>
      

Remember that the tegra_vnet driver is not officially supported for x86 to Jetson communication. You may need to explore alternative solutions or wait for official support from NVIDIA for this specific use case.