Re: multiple drivers, single device (was Re: Announce: Linux-next (Or Andrew's dream :-)))

Linus Torvalds
2008-02-12T18:30:44Z

On Tue, 12 Feb 2008, Jeff Garzik wrote:

> Greg KH wrote:
> > The work I'm doing here is for stupid PCI firmware engineers, who have
> > created devices that are different things, all bound up under the same
> > PCI device. I'm thinking of watchdog timers and random number
> > generator and i2c controller on the same PCI device, or even the more
> > basic, frame buffer and DRM access to the same PCI video device.
>
> Yes, that has a known solution: have your driver register i2c, rng, watchdog,
> etc. functions.
>
> Works just fine inside today's infrastructure, no changes needed.

Indeed. If you have a multi-function device that shows up as a single PCI
function, just make it have its own "private bus", and make it show up as
a "devices within a device".

Create the fake PCI subdevices that have no "real" counterpart, except as
parts of the stupid device that couldn't be bothered to be seen as
multiple _real_ functions.

That not only solves the infrastructure issues, it's actually The Truth
with capital letters. It is, after all, how the device actually works
internally.

Linus