connector/edid probing races

[Dave Airlie]

Talk to Jonas (jadahl) on irc, he had 3 mutters running and on hotplug
all 3 of them were diving into the connector getting code. Now I think
we can avoid this in userspace by not probing when not owning the VT,
but it's still messy behaviour.

It looks like one thread does a getconnector, this fills out the EDID
blob with a specific blob id,
then second thread does getconnector, which replaces the EDID blob
with another one
the first thread calls get property blob, but the blob id it is
looking for is destroyed.

Ideas?
Dave.