PERFORCE change 75921 for review

[Marcel Moolenaar]

On Apr 24, 2005, at 10:49 PM, M. Warner Losh wrote:

> In message: <200504250459.j3P4xWxs057683 at repoman.freebsd.org>
>             Marcel Moolenaar <marcel at freebsd.org> writes:
> : http://perforce.freebsd.org/chv.cgi?CH=75921
> :
> : Change 75921 by marcel at marcel_nfs on 2005/04/25 04:59:01
> :
> : 	Allow VGA resources across PCI-PCI bridges. Required to
> : 	support a PCI based VGA driver with the VGA hardware
> : 	behind a PCI-PCI bridge.
>
> WE need to make sure that the ISA bit and VGA bits are set properly on
> those bridges with vga children and peers of bridges with vga
> children before allowing this...

Ideally, yes. But since only one PCI device of class display and
subclass VGA can have the legacy VGA addresses enabled and we're
not mucking with the system configuration in that respect, we're
not really doing anything dangerous by allowing the VGA addresses
without such scrutiny provided we don't try to allocate those
addresses for any ol' VGA display device that we find on the PCI
busses in the system.

-- 
  Marcel Moolenaar         USPA: A-39004          marcel at xcllnt.net