Re: Please revert 5adc55da4a7758021bcc374904b0f8b076508a11 (PCI_MULTITHREAD_PROBE)

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Wed, 9 May 2007 10:09:33 -0700 (PDT),
david@lang.hm wrote:

> > Hm, so that sound like a case for a distinct setup() routine:
> >
> > 1. bus calls ->probe(), which return synchronously
> > 2. bus calls ->probe_async() for all devices (optional)
> > 3. bus waits for all probes to finish
> > 4. bus calls ->setup() for all devices (which does the registering)
> 
> this is exactly what I've been trying to describe.

Nearly, but with a slightly different spin...

> 
> > (->setup() can but need not be sync, although it should be for your
> > case)
> 
> if it's not sync then you have race conditions again

...but not all busses will care. If your bus wants to enforce ordering,
it must enforce it to be sync. If your bus allows hotplug and calling
setup() later on, it may also allow async. (setup() is a bit
dual-purpose in this idea.)