I think the appearance is Serial Number of my HiKEY device has gone.
as a comparison, once i connected a normal Android phone as Fastboot mode, by running dmesg:
[ 1855.045068] usb 1-2: new high-speed USB device number 6 using ehci-pci
[ 1855.179383] usb 1-2: New USB device found, idVendor=0bb4, idProduct=0c01
[ 1855.179401] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1855.179410] usb 1-2: Product: Android
[ 1855.179419] usb 1-2: Manufacturer: MediaTek
[ 1855.179426] usb 1-2: SerialNumber: 0123456789ABCDEF
you can see the last line of Serial Number of an Android phone connected, but my HIKEY device never shows the last line.
Maybe "Fastboot" function of my HIKEY has gone or broken?
my HIKEY was running fine, but after i run "sudo python hisi-idt.py -d /dev/ttyUSB0 –img1=l-loader.bin" again, i can not use fastboot function as it always shows <waiting for device>