Subject: Re: PCI and subsystem IDs.
To: Michael Richardson <>
From: Chris G. Demetriou <>
List: tech-kern
Date: 10/06/1998 11:50:34
Michael Richardson <> writes:
>   Do we currently have any support for probing based on PCI Subsystem Vendor
> IDs and Subsystem IDs?

Some devices certainly do check those things, yes.

>   From reading pcivar.h and pcireg.h, it appears that we don't even collect
> that info.
>   I expect that we should. Comments?

Perhaps.  I've yet to see consistent enough usage and application of
them to decide how to represent them.

Specifically, the things i'm wondering are:

(1) what is the namespace for subsystem vendor IDs?  (I've heard "same
as vendor IDs," but haven't had C&V quoted at me, so i'm
skeptical. 8-)

(2) what is the namespace for subsystem IDs?  I.e. is it per subsystem
vendor, or per prod/vendor/subsystem_vendor?

The answers to those questions are necessary before anything 'useful'
can be done around recording them in a consistent manner.

There's also the issue that, in the largest share of devices i've
seen, if they're present at all they're completely ignorable.
There're only two cases i've heard of where paying attention to them
are important, and of those, only one has a driver in the source tree.

Chris Demetriou - -
Disclaimer: Not speaking for NetBSD, just expressing my own opinion.