Luckfox Forums

Posted: **2026-01-25 17:13**

Problem

On my PC, the Luckfox Pico Zero is consistently detected as the USB device 2207:0019 during normal boot.
However, when attempting to enter flash mode, the device with ID 2207:110c never appears. In this state, 2207:0019 also does not show up.

After resetting the board, it is once again detected as 2207:0019, and I can access it normally via SSH or Samba.

Investigation

I tested different USB cables and operating systems (Windows 11 and Ubuntu 24.04), but the issue persisted.
When I tried a different USB port, the problem was unexpectedly resolved. This led me to systematically test all USB ports on my PC.

The following USB ports worked correctly in both normal boot and flash mode:

usb 3-2 (front, USB-A)
usb 3-3.1 (back, USB-A)
usb 3-3.2 (back, USB-A)
usb 3-3.3 (back, USB-A)
usb 3-1 (back, USB-A)

In these cases, dmesg showed:

Code: Select all

sudo dmesg -w
... new high-speed USB device number 78 using xhci_hcd
... New USB device found, idVendor=2207, idProduct=110c, bcdDevice= 1.00
... New USB device strings: Mfr=0, Product=0, SerialNumber=0

The following USB ports could detect the device during normal boot, but failed to detect it in flash mode:

usb 3-4 (front, USB-A)
usb 3-5 (front, USB-C)

In these cases, dmesg showed:

Code: Select all

sudo dmesg -w
... Device not responding to setup address.
... device not accepting address 77, error -71
... unable to enumerate USB device

When the Luckfox Pico Zero was connected to USB 3-5 through an external USB hub, the PC failed to detect the Rockchip USB device in both flash mode and normal boot mode:

Code: Select all

sudo dmesg -w
... Cannot enable. Maybe the USB cable is bad?
... attempt power cycle
... Cannot enable. Maybe the USB cable is bad?
... unable to enumerate USB device

Findings

These results indicate that the issue is USB-port specific, rather than being caused by the Luckfox Pico Zero hardware, USB cables, or flashing procedure.

Further Question

Is it possible to mitigate this issue from the Luckfox device side?
For example:

Can the behavior of `2207:110c` be made more similar to `2207:0019`?
Is there a way to improve compatibility with a wider range of USB host hardware?

Posted: **2026-01-26 1:43**

Hello, the prompt "Cannot enable. Maybe the USB cable is bad?" usually indicates a problem with the differential signal of the USB cable (including the cables of the USB HUB and the extended cables inside the case).
The burning mode generally uses the internal BOOTROM of the chip or the usbplug.bin burned into the flash externally to set up the USB, but both of these are closed source, and Rockchip does not release the relevant information, so it is impossible to optimize or modify them.
The advice we can offer is to avoid connecting through a USB HUB as much as possible, or choose a HUB that supports external power supply. A stable power supply can make the signal more stable and may improve this situation.

Luckfox Forums

Luckfox Pico Zero cannot enter MaskROM (2207:110c) on some USB ports — error -71, fixed by switching port

Luckfox Pico Zero cannot enter MaskROM (2207:110c) on some USB ports — error -71, fixed by switching port

Re: Luckfox Pico Zero cannot enter MaskROM (2207:110c) on some USB ports — error -71, fixed by switching port