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SubjectRe: Please revert 5adc55da4a7758021bcc374904b0f8b076508a11 (PCI_MULTITHREAD_PROBE)
On Wed, 9 May 2007, Cornelia Huck wrote:

> 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.)

if you want the registration to use hotplug and be async then do do the
registration during step 2 and make step 4 be a noop, in fact some drivers
may do all their work in step 2, while others (everything currently) will
do all their work during step 1

David Lang


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