[RFSOC 4x2] USB Connect Issue: No IP Detected

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Board: RFSoC 4x2 Version: v3.0.1

Problem description: I connect the PYNQ board to my PC via USB and access Jupyter Notebook over this USB connection. This setup worked without any issues as recently as last Wednesday. Now, without any intentional configuration changes, the PYNQ board reports “No IP detected” for the USB network interface, and USB-based access to Jupyter Notebook no longer functions. The board boots normally and all status LEDs are in their expected states. Accessing Jupyter Notebook over Ethernet still works correctly. The issue occurs only when using the USB connection.

Troubleshooting attempts and observations：

  • Tried different USB cables

  • Power-cycled the board and rebooted the PC

  • Reflashed the SD card with a fresh PYNQ image

  • Verified USB gadget setup on the board via a USB-UART connection

    • The PC shows a connection notification when the USB-UART cable is plugged in
    • Gadget exists under /sys/kernel/config/usb_gadget/
    • rndis.usb0, acm.usb0, and mass_storage.ms0 are present and linked
    • USB network interface reports “No IP detected”

  • Checked behavior on the Windows 11 host

    • When plug in the USB Device port (used for Jupyter access), PC shows no connection notification
    • No usable USB network adapter appears
    • No stable COM port is detected for the USB Device port

Questions： How can I restore and recover the USB Device connection on an RFSoC 4x2 board when it previously worked but now no longer works correctly?

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Hi @Gloria-Gly

You’ve done a good job of eliminating most of the common issues.

Could you also try a new/different SD card as well? And, if possible, try with a different PC as well.

Additionally, with the USB gadget cable unplugged, could you:

  • Connect to the board via serial (e.g. using Putty)
  • Boot the board
  • Once the board has fully booted, from the serial terminal could you run sudo dmesg
  • Plug in the USB gadget cable between your Windows PC and the board and wait a few seconds.
  • Run sudo dmesg again
  • Report back any new messages between sudo dmesg calls.

This should tell us a bit more info.

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Hi @joshgoldsmith

Thank you for following up and for the detailed suggestions.

I tried using a different computer before. I tested the board with both my primary Windows PC and another laptop, but the behavior is the same on both systems and this did not resolve the issue.

Regarding the SD card suggestion, I have not yet tried a different SD card. At the moment, I only have a 16 GB SD card available. If switching SD cards is required, I would need to purchase a new one, which may take some time. I also noticed that some users on the forum reported improvement after switching from a smaller SD card (e.g., 8 GB) to a larger one (e.g., 128 GB). In your experience, would you recommend trying a 128 GB SD card in this case?

In the meantime, I performed the checks that I could do immediately. Following your instructions, I captured the sudo dmesg output before and after plugging in the USB gadget cable and compared the two logs. There are no new kernel messages between the two sudo dmesg calls; the outputs are identical when plugging in the USB gadget cable.