On 13 Nov 1996 17:30:17 -0500 
 Michael Graff <explorer@flame.org> wrote:

 > I would rather have a method to allow probing busses in specific order.

We already have this.  For example, in -current, PCI is checked, then
EISA, then ISA.

The infrastructure for it is basically already there in the ISA case,
as well... For example, the ISA code will have to know what things
it needs early on.  It would probably keep some sort of list of these
things... I'm thinking specifically of the pcmcia chipset... you want
to attach the pcic, the pccard slots, and the devices in the pccard
slots before they're found as "ISA" devices.

You also need a way of deferring something... a simple comparison of
names will work...

 > There are other reasons to do this as well, and I have seen discussion
 > on the same.  In fact, there are very good reasons to control the probe
 > ordering on things like the ISA bus in general, since some driver probes
 > munch on other device's toes.
 > 
 > I believe FreeBSD has a priority-based scheme.  I propose we adopt
 > something like it.

How does their priority-based scheme work?

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
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