using the MDK with embedded board

[rienafairefr]

Hi,

we're trying out the nrf52840-mdk boards for www.iot-lab.info , and we're running into some weird USB issues.
We're trying to connect the mdks to an embedded computer. Our boards are based on a variscite board, kind of like a raspberry pi compute module. It's running a 3.19.0 kernel with a custom linux distro on top, using Yocto. We're getting no usb device visible, and this is spamming in dmesg:

[ 6543.362335] usb 1-1.2: new high-speed USB device number 71 using ehci-omap
[ 6543.505157] usb 1-1.2: device descriptor read/all, error -71

In parallel we have some mdks connected to raspberry pis and they're all working fine, so we suspected there's something wrong in our kernel (the rpis are running kernel 4.4.13). We also have some DAPlink boards (microbit) running fine on these gateways, so we suspect it's something to do with the usb cable, or the usb hub on the mdk board.

Any info from you guys on the kernel versions support for the microchip hub usb, maybe some modules need to be added, or any clue to what we could do to make our board like our mdks ? ;-)

[caizelin]

@rienafairefr Sorry for the late reply. Is it possible to update your kernel(like rpis)? Or try to attach another usb hub that can be supported by your host. As we know the RPI also has a usb hub chip inside.
Pls let me know if you have any update.
Thanks.