DMR Radio connected via RNDIS to Linux Board

Question

I am trying to connect a DMR Hytera radio to a Linux board using RNDIS driver.

Watching How to configure unknown usb device as ethernet on Linux host? and rndis_host: support Hytera digital radios , I have modified driver rndis_host.c and rebuild module rndis_host.ko.

Using an appropriate ethX.conf I see that the network was successfully created and all works fine.

I have a problem: all works fine only from the second time I connect the radio to board. The first time I receive:

rndis_host 2-2:1.0: RNDIS init failed, -110
rndis_host: probe of 2-2:1.0 failed with error -110

So I added rndis_host in file /etc/modules in order to preload the module. This correct the first radio connection but not if I switch on the board with the radio already connected and switched on. In this case I receive always -110 error (timeout error). I try also adding rndis_wlan in /etc/modules but nothing changed.

I think there is a timeout problem during boot between driver loading and usb detection, but I am not able to solve it.

Someone can help me?

Thank you