usb_autopm_put_interface — decrement a USB interface's PM-usage counter
| void usb_autopm_put_interface ( | struct usb_interface * intf ); | 
   This routine should be called by an interface driver when it is
   finished using intf and wants to allow it to autosuspend.  A typical
   example would be a character-device driver when its device file is
   closed.
   
   The routine decrements intf's usage counter.  When the counter reaches
   0, a delayed autosuspend request for intf's device is attempted.  The
   attempt may fail (see autosuspend_check).
   
This routine can run only in process context.