Radxa Zero as USB C gadget for iPad Pro

Zero Series
22

I found this when my system is starting up:

[ 5.750471] usbcore: registered new interface driver brcmfmac
[ 5.793344] brcmfmac mmc0:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.radxa,zero.txt failed with error -2
…
[ 6.511010] usb0: HOST MAC f2:e5:df:c4:e9:d7
[ 6.511025] usb0: MAC be:e9:e1:6d:d9:a8
[ 6.514534] dwc2 ff400000.usb: bound driver configfs-gadget
[ 8.110900] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[ 8.159683] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/6 wl0: Feb 27 2018 03:15:32 version 7.45.154 (r684107 CY) FWID 01-4fbe0b04

My lsmod command:

usb_f_ecm 24576 2
u_ether 28672 1 usb_f_ecm
libcomposite 73728 8 usb_f_ecm

24

I think that g_ether already creates an USB-ethernet gadget by itself, so that you cannot use configFS anymore to create additional gadgets/devices.

Oh, it is u_ether! OK, now I am lost too.

25

Hm. New clean installation of the same system, now on the internal MMC, and it does not work again. I still have no idea why it previously suddenly started working on the SD card (and it still does). Neverending story…

26

Problem solved.

Comparison of the working and non-working installation showed the key difference is dhcpcd.service running on the former one, but not on the latter one. The dhcpcd actually automatically activates and configures the new network device as soon as it appears in the system. If it is not activated on the side of the device, it is not detected by the host either!

For some reason, there seems to be some difference between the images. I do not remember to have activated dhcpcd myself before.