0

A USB root hub of mine sometimes stop working: though it shows up in lsusb, nothing happens when a device is plugged in, not even an error message in dmesg. So I attempted to reset it by unbinding and rebinding the root hub to its underlaying PCIe interface. I ran:

printf "0000:03:00.3" > /sys/bus/pci/drivers/xhci_hcd/unbind
printf "0000:03:00.3" > /sys/bus/pci/drivers/xhci_hcd/bind

In which 0000:03:00.3 is the PCIe address of the root hub, as shown by the iSerial field in lsusb -v -s bus_number_of_root_hub:1. lspci also shows similar information:

03:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Raven USB 3.1 (prog-if 30 [XHCI])
        Subsystem: Lenovo Raven USB 3.1

However, the bind step above results in a printf: write error: No such device error. But lspci still contains 03:00.3. Also, nothing in dmesg. I would like to know why I can't rebind this device that clearly exist, or if it's some other problem.

For comparison, the other USB root hub I have, which connects to Bluetooth and webcam, though it fails occasionally, can be reset using the above method. Also, when using Windows, nothing breaks, so I don't think anything is wrong with my hardware. I'm running Ubuntu 19.10, kernel version 5.3.0.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.