This power state change is communicated by {HEAD ~ the device controller} to {TAIL ~ a device driver} in response to the device removal signal 
to
This power state change is communicated by { HEAD ~ the device controller } to { TAIL ~ a device driver } in response to the device removal signal
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH