Subject: Re: PCI and subsystem IDs.
To: Todd Whitesel <>
From: Soren S. Jorvang <>
List: tech-kern
Date: 10/07/1998 00:23:08
On Tue, Oct 06, 1998 at 03:11:20PM -0700, Todd Whitesel wrote:
> > 'Subsystem Vendor IDs can be obtained from the PCI SIG [...]'
> > Whatever that means.
> Um, it just means that you're supposed to register with the PCI SIG for an
> assigned number, like purchasing a 24-bit ethernet address block from IEEE.

Yes, but Chris asked if they are assigned from the same list
as non-sub vendor IDs or from a seperate list (no mention
of such a thing on

It does say (my emphasis) '*Subsystem Vendor IDs* can [..]'.

Who knows for sure?

> > 'Values for Subsystem ID are vendor specific.'
> > Whatever that means.
> Um, once you have obtained a unique vendor ID, you can manage the assignment
> of the subsystem ID's in any way you see fit.

But are they supposed to be from the same (private) list
as the vendors product IDs, or are they not even
required to be product-ID-like (eg. serial numbers)?

Or what?

> > Anyway, what is important in relation to NetBSD is whether
> > drivers need the sub IDs for matching/attachment, and I
> > believe that is not the case.
> I think you are correct, although conceivably one day they might be required
> for quirk table purposes.

Yes, but that isn't handled by the autoconfiguration process,
so the driver can just use PCI_{VENDOR,PRODUCT}() on PCI_SUBID_REG
in the quirk implementation.

Of course, having convenience variables in the attach structure
may be helpful (in (PCI) particular, the BIST register is accessed
by many PCI device drivers), but it is not a requirement.