RPi Zero USB OTG (usb-ethernet device)

[jbeale]

I'm trying to use my Raspberry Pi Zero V1.2 with current Raspbian Lite:

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Linux rp01 4.14.50+ #1122 Tue Jun 19 12:21:21 BST 2018 armv6l GNU/Linux

in the USB OTG ("usb gadget") mode, to appear as a USB-Ethernet device to another PC (in this case, a MiniPC running Ubuntu 18.04.1).

Following an online tutorial I added a 'modules_load' part to /boot/cmdline.txt:

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dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=PARTUUID=8f416024-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait modules-load=dwc2, g_ether

and also a line with 'dtoverlay=dwc2' to /boot/config.txt

I am using the hardware serial port on the GPIO pins to see the boot messages from the Pi Zero. I do see that the Ubuntu system tries to attach to it, however this is what 'dmesg' says:

[ 180.487085] usb 1-4: new high-speed USB device number 6 using xhci_hcd
[ 185.675209] usb 1-4: device descriptor read/64, error -110
[ 201.288188] usb 1-4: device descriptor read/64, error -110
[ 201.523950] usb 1-4: new high-speed USB device number 7 using xhci_hcd
[ 206.664268] usb 1-4: device descriptor read/64, error -110
[ 222.281386] usb 1-4: device descriptor read/64, error -110
[ 222.389581] usb usb1-port4: attempt power cycle
[ 223.041478] usb 1-4: new high-speed USB device number 8 using xhci_hcd
[ 228.297737] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[ 233.673482] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[ 233.881767] usb 1-4: device not accepting address 8, error -62
[ 234.009774] usb 1-4: new high-speed USB device number 9 using xhci_hcd
[ 239.049619] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[ 244.425463] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[ 244.633519] usb 1-4: device not accepting address 9, error -62
[ 244.633791] usb usb1-port4: unable to enumerate USB device

anything obvious I'm doing wrong?

EDIT: SOLVED!
I had an extra space after the comma in my cmdline.txt before g_ether and removing that space was the trick. Ubuntu now shows:

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Bus 001 Device 010: ID 0525:a4a2 Netchip Technology, Inc. Linux-USB Ethernet/RNDIS Gadget

I had copy-and-pasted the whole line exactly from a web page tutorial, but it had been translated from French, and perhaps Google Translate helpfully added a space after the comma.
There is an English tutorial here: https://learn.adafruit.com/turning-your ... net-gadget

EDIT2: Not Quite Solved for Windows 10

Although the RPi Zero-as-USB-Ethernet-Gadget works fine with a Linux host, it turns out there is trouble using it with a Win10 laptop. All the online tutorials I've found on this issue, claim I should be able to go through Device Manager in Win10 to manually change the installed driver to a Microsoft RNDIS network type, but on my system, Windows sees the RPi Zero USB as a serial device (COM5) and the device driver dialog refuses to present any drivers from Microsoft or anyone else, which are not serial devices. Perhaps Windows has recently changed to "helpfully" prevent you from choosing the wrong device type, but that means I'm locked out of using this as a network device. Any ideas? FWIW, Win10 says USB\VID_0525&PID_A4A2

Supposedly this driver would work, but it is apparently no longer available for download.
http://www.catalog.update.microsoft.com ... 8e439f90a2

EDIT3: Turns out that only one laptop has a problem.

I tried the same RPi Zero connected to a different Windows 10 laptop, and that one worked right away with Device Manager showing the Pi Zero as "USB Ethernet/RNDIS Gadget" without any user action at all. The network connection operates as expected. The difference between the two laptops remains a mystery.

[fkopac]

I had unexplained problems with the RNDIS Gadget too. I had to manually delete the driver in the device manager and then it worked.