Banana Pi M2-Zero: USB Host issues

[Tomash]

After some frustration with poor support for Banana Pi M2 Zero board by the manufacturer and not a very active community on Banana Pi forums, I stumbled upon Armbian and found out there's a CSC for building Armbian for this board. And because I'm having issues with wifi on the images found on Banana forums, with all images being old and based on kernel 3.4 -- wifi disconnects with some weird firmware errors in dmesg after about 3 minutes of running, requiring reboot to get back up again -- I was happy to read Armbian runs fine on BPI-M2Z for some folks here.

So I did the build process, twice, so that I have two images to test, one with kernel 4.19 and one with 5.1, both running Ubuntu 18.04 as I'm more familiar with this than with Debian.

 

It runs good. Great work, I'm really in awe.

 

There is one issue, though: no usb device (and I'd love at least a keyboard) connected to "OTG" microusb port on the board works. The hardware stack is fine since on Raspbian 9.4 with 3.4 kernel I have it working with USB keyboard, mice, usb hubs, even a wifi dongle is detected and I can modprobe a required module. But in Armbian, regardless of which of the two kernels I try, there's no trace in dmesg that any USB device has been connected (the board does report as UART/serial device when I use same USB port to connect it with my Ubuntu PC). lsusb shows three hubs but nothing beyond that.

 

I read Vincent's blogpost [1]. I checked dr_mode in dtb/dts file and it's "host", as I guess it should be. Can't compare it with the usb-working Raspbian since it has no dtb files in /boot.

 

[1] https://vjordan.info/log/fpga/nanopi-neo-usb-otg-with-armbian-mainline-4x-kernel.html

[chwe]

haha my fault.. I added a more or less proper support to csc for the board back then..

 

https://github.com/armbian/build/blob/e8e0c698f19204fd63b89132867725ce7dade8db/config/boards/bananapim2zero.csc#L7

if you disable g_serial, I assume it will just work as USB otg but not tested, don't even know where in my 'retired electronics box' the board actually is..  

[Tomash]

Can I only disable it at image build time, or can I remove this module from a working image and have a working OTG?

 

Thanks for the CSC. I'm never again buying any SBC from Banana brand, though 

[Tomash]

Turns our dr_mode was "otg", changed it to host and usb peripherals work now, great!