23-Aug-2002
  
  The "ohci-hcd" driver is a USB Host Controller Driver (HCD) that is derived
  from the "usb-ohci" driver from the 2.4 kernel series.  The "usb-ohci" code
  was written primarily by Roman Weissgaerber <weissg@vienna.at> but with
  contributions from many others (read its copyright/licencing header).
  
  It supports the "Open Host Controller Interface" (OHCI), which standardizes
  hardware register protocols used to talk to USB 1.1 host controllers.  As
  compared to the earlier "Universal Host Controller Interface" (UHCI) from
  Intel, it pushes more intelligence into the hardware.  USB 1.1 controllers
  from vendors other than Intel and VIA generally use OHCI.
  
  Changes since the 2.4 kernel include
  
  	- improved robustness; bugfixes; and less overhead
  	- supports the updated and simplified usbcore APIs
  	- interrupt transfers can be larger, and can be queued
  	- less code, by using the upper level "hcd" framework
  	- supports some non-PCI implementations of OHCI
  	- ... more
  
  The "ohci-hcd" driver handles all USB 1.1 transfer types.  Transfers of all
  types can be queued.  That was also true in "usb-ohci", except for interrupt
  transfers.  Previously, using periods of one frame would risk data loss due
  to overhead in IRQ processing.  When interrupt transfers are queued, those
  risks can be minimized by making sure the hardware always has transfers to
  work on while the OS is getting around to the relevant IRQ processing.
  
  - David Brownell
    <dbrownell@users.sourceforge.net>