Subject: Re: looking for devices on PCI bus
To: Michael Lyle <>
From: Manuel Bouyer <>
List: tech-kern
Date: 05/02/2001 14:03:21
On Tue, May 01, 2001 at 05:09:24PM -0700, Michael Lyle wrote:
> On Tue, May 01, 2001 at 05:07:08PM -0700, Chris G. Demetriou wrote:
> > It would seem to be a mistake to do something which:
> > 
> > 	* involved significant code size increase, or
> > 	* involved significant data size increase
> > 
> > to accomodate something which happens almost never.
> The thing is.. the table is small-- how many pci devices are in the
> system, anyways?  and you -can't- do hotplug right without this kind of
> functionality.  e.g. you could use an exceptionall small linked list for
> this purpose, e.g. <20 bytes per device.

And we may need such a table or list if we want to provide a list of
PCI devices to procfs or sysctl (but, as I think about it, if we do this
we should provide the whole autoconf tree instead)
This list probably exists in the autoconf tree anyway, but only for configured
devices I guess.

> It also assumes that rescanning things after beginning to use them is
> safe-- which might not necessarily be a safe assumption with broken
> hardware.

Do you have example of such hardware ?
This would mean we can't access PCI config space registers once the device
is in use. I suspect this would break a lot of other things.

Manuel Bouyer, LIP6, Universite Paris VI.