title: Linux USB driver probe not called if device already plugged
body: <p>If I use a modified usb skeleton driver on Linux and I insmod the module with the USB device already plugged in, the probe function doesn't get called. I need to unplug and replug the device in order for the driver to be activated.
  This is not the case for e.g. the serial drivers, I made some tests.
  Is there a reason for this? How do I get the probe function to get called?</p>