ack_busy_X into
firewire-core's Config ROM reader, such that at least firewire-core's
probing and /dev/fw* creation are successful.  This still leaves the
problem that userland processes are facing transaction failures.
gscanbus's built-in retry routines deal with them successfully, but
neither kino's nor dvgrab's do ever succeed.

But at least DV capture with "dvgrab -noavc -card 0" works now.  Live
video preview in kino works too, but not actual capture.

One way to prevent Configuration ROM reading failures in application
programs is to modify libraw1394 to synthesize read responses by means
of firewire-core's Configuration ROM cache.  This would only leave
CMP and FCP transaction failures as a potential problem source for
applications.

Reported-and-tested-by: Thomas Seilund <tps@netmaster.dk>
Reported-and-tested-by: René Fritz <rene@colorcube.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
=.