Hi Jerry,

From this information, I would think there is something wrong with the

device bootloader firmware. But please create a new ticket on https://sourceforge.net/p/dfu-util/tickets/ and provide the information that is requested. Note also that the latest release of dfu-util is 0.10 and you are using a fairly old version.

Regards, Tormod

On Sat, Apr 3, 2021 at 11:35 PM Jerry wrote:

Recently I bought a device ATUSB which uses dfu-util 0.7 to write the flash. I use my Raspberry Pi 4 and it runs Ubuntu 20.04. After installing dfu-util 0.7, I run the following commands to flash atusb firmware into it. dfu-util 0.7 Found Runtime: [20b7:1540] devnum=0, cfg=1, intf=1, alt=0, name="UNDEFINED" Did not find cached descriptor WARNING: Can not find cached DFU functional descriptor Warning: Assuming DFU version 1.0 Run-time device DFU version 0100 Claiming USB DFU Runtime Interface... Cannot set alt interface zero

After this error is shown, the LED on my ATUSB is blinking. Any idea? I have tried reinstalling dfu-util or rebooting, but none of them work. Any advice is appreciated.