In message <Pine.BSF.4.10.10106051912280.20600-100000@bluebottle> Nick Hibma writes:
: > > - Some dummy driver which grabs the resource. The dummy driver would
: > > need to be unloaded when the actual driver needs the resources.
: >
: > This sounds attractive, but it's hard to find the dummy driver when
: > you want to open the bidding for one or more devices again. You also end
: > up with the ugly case where the device has more resources than the driver
: > uses; you end up needing a placeholder of some sort for these as well, so
: > you might as well just built it into the way the bus thinks about child
: > devices and be done with it.
:
: It was suggested some time ago to do this by having a priority value
: that indicates a dummy, say -10000. When a driver is loaded, all dummies
: are detached and the probe is restarted. The dummies are quiet if not
: cold booting to avoi a storm of dummies announcing themselves again and
: again.
There are some subtle problems with this approach. Specifically, if I
have a card in a bus that can live at any address. I load a driver
for this card, so the bus reprobes. If all I have to go by is these
drivers that have reserved resources, then if we detach them all
before doing this, we could have a situation where order matters and
the device could get one of the other device's resources. I also
recall having a problem by not detaching all the devices at once, but
I can't recall what it is at the moment.
Warner
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