Re: LANANA: To Pending Device Number Registrants

David Brownell
2001-05-17T17:05:14Z

> For identifying this is probably the right approach. However identifying is
> not enough, as the ioctl discussion has shown. Capabilities are needed. How
> can the device registry provide that information ?

My feedback on "device registry 0.1" was that I really liked the
approach of _modeling_ devices by attributes ... which reminded me
of the good things in "attribute based naming" a la X.500/LDAP
models. I suspect 0.2 went too far, using XML to expose those
attributes to userspace ... :)

If each device had a directory node, those directory nodes could be
grouped as a "registry" ... the directory contents would list the various
bus-specific or type-specific capabilities/attributes. Would those
directory nodes be the /dev/... or /devfs/... nodes? I suspect not.

> If we register it together
> with the device, we might spend a lot of resources needlessly and can't deal
> with devices whose capabilities change dynamically.

So obviously such a registry should query the drivers/busses directly.

> In addition how do we export the information ? Proc ?

I think Tim has some ideas here, given a patch I scanned recently...

- Dave