Bug? PCI link device _SRS

[Brown, Len]

John,
Dunno if FreeBSD works the same way,
but we recently fixed a couple of interesting
platform isssue using PCI Interrupt Links
on Linux.

1. The enabled bit from _STA for
   PCI Interrupt Link devices is meaningless
   on many platforms, ignore it.

   If a platform gives you a _CRS IRQ that
   is outside the _PRS list, then do no
   stick with the _CRS -- select
   a new (valid) one from the _PRS list.

   If a platform gives you a _CRS IRQ that
   is different from the _SRS you just
   invoked.  Assume that the _SRS worked
   and that the _CRS is bogus.
   
http://bugzilla.kernel.org/show_bug.cgi?id=1581

2. Blindly programming all PCI Interrupt Link Devices
turns out to be a bad idea.  Instead, they should
be programmed only when PCI devices using them are
installed and enabled in the system.
http://bugzilla.kernel.org/show_bug.cgi?id=2574

cheers,
-Len