I am using a USB 3G stick on a RPI B+ (3.18.7+) to ftp measurements from a sensor platform. To limit RF interference, and save power, I am turning it on and off a lot (which on the B+ is now possible, using the "hub-ctrl" command.
The problem is that, after switching it on and off for some tens of cycles, the device is no longer detected properly when switched on. (for full detail see http://www.raspberrypi.org/forums/viewtopic.php?f=28&t=101005)
Does anybody know if there is some sort or "restart" or "reset" that I can do to get usb to re-initialise and re-enumerate everything on the bus? (usb is not a kernel module on the pi, so loading and unloading is not possible)
Or is there maybe another way to do this switching, not using hub-ctrl (I suspect it is not de-registering the stick before it cuts the power or something)