Re: acpivga(4) v. MI display controls

[der Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>> The task is not trivial.  On modern x86, practically *everything*
>> that attachs has an ACPI counterpart.  In a way we are thinking this
>> backwards: the attachment should perhaps be done via ACPI that has
>> information about the "natural" device tree

ACPI may be the source of the information, but that doesn't mean it has
to be how the autoconf tree is constructed.

Compare and contrast with how NetBSD/sparc uses the OF (or is it OBP?
I'm not sure) device tree to drive autoconf, but doesn't have a device
node corresponding to OF that everything attaches under; it just uses
the OF tree as the source of the data about what exists where.  (Well,
much of it; autoconf doesn't totally mirror OF, eg, in SCSI device
attachment.)

> This should be solved once and for all, for all acpi(4) and for all
> pci(4), isa(4), ... Otherwise we end up with god-awful mess.

Has anyone tried handling it by giving devices multiple parents?  This
would clean up some other things, such as wscons (there arguably ought
to be something which is parented to both the wsdisplay and the wskbd).
I have no idea how much hair it would introduce, though.

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