Monitoring USB Bandwidth on Jetson Orin Nano

Issue Overview

Users are experiencing difficulties monitoring USB bandwidth on the Jetson Orin Nano running JetPack 6.0. The primary issue is the inability to use the "usbtop" tool due to the absence of the usbmon module in the kernel configuration. This problem prevents users from effectively monitoring the active USB bandwidth of devices such as webcams, which is crucial for performance optimization and debugging in various applications.

Possible Causes

1. Kernel Configuration: The CONFIG_USB_MON option is not set in the kernel configuration, preventing the use of usbmon and related tools.

2. JetPack Limitations: The default JetPack 6.0 installation may not include necessary modules or configurations for USB monitoring.

3. Incompatibility: The usual tools for USB bandwidth monitoring might not be compatible with the Jetson Orin Nano’s architecture or JetPack version.

Troubleshooting Steps, Solutions & Fixes

1. Verify Kernel Configuration:
   Check the current kernel configuration for USB monitoring support:

   grep CONFIG_USB_MON /usr/src/linux-headers-5.15.136-tegra-ubuntu22.04_aarch64/3rdparty/canonical/linux-jammy/kernel-source/.config
   

   If the output shows "# CONFIG_USB_MON is not set", proceed to enable it.

2. Enable USB Monitoring in Kernel:
   a. Obtain the kernel source for your specific L4T release:

   • Check your L4T version: head -n 1 /etc/nv_tegra_release
   • Download the corresponding kernel source from: https://developer.nvidia.com/linux-tegra

   b. Configure the kernel:

   • Match the configuration to your running Jetson, including CONFIG_LOCALVERSION (which should be "-tegra")
   • Use a dependency-aware tool like menuconfig or nconfig to add CONFIG_USB_MON as a module

   c. Build the module:
   Follow the Jetson Linux Developer Guide for kernel customization:
   https://docs.nvidia.com/jetson/archives/r35.3.1/DeveloperGuide/text/SD/Kernel/KernelCustomization.html

   d. Install the new module:

   • Copy the compiled module to the appropriate location on your Jetson Orin Nano

3. Alternative Approach (Less Complex):
   If you prefer not to rebuild the entire kernel, you can add CONFIG_USB_MON as a module:

   • Follow steps a and b from the previous solution
   • Build only the USB_MON module
   • Copy the module to the appropriate location on your Jetson

4. Full Kernel Rebuild (If Necessary):
   If you decide to set CONFIG_USB_MON=y instead of as a module:

   • Rebuild the entire kernel and all modules
   • Copy the new kernel and all newly compiled modules to their respective locations on the Jetson

5. Verify Installation:
   After installing the new module or kernel:

   • Attempt to load the usbmon module: sudo modprobe usbmon
   • If successful, proceed to install and use usbtop

6. Install and Use USB Monitoring Tools:
   Once usbmon is available, install usbtop or other USB monitoring tools:

   sudo apt-get update
   sudo apt-get install usbtop
   

7. Monitor USB Bandwidth:
   Use usbtop to monitor USB bandwidth:

   sudo usbtop
   

8. Explore Alternatives:
   If issues persist, consider alternative methods for monitoring USB bandwidth:

   • Use system tools like lsusb and cat /sys/kernel/debug/usb/devices for basic USB information
   • Explore NVIDIA-specific tools or APIs that might provide USB bandwidth information

9. Seek Community Support:
   If problems continue, engage with the NVIDIA Developer Forums or Jetson community for more specific assistance or alternative solutions.