Thank you for the extended description.  Unfortunately, I don't know
enough about the PNPBIPS/PNPACPI subsystem to comment further on the
patch, but it does look useful.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh