Fix FCP and ARM source node ID on firewire-core

The firewire-core (juju) backend of libraw1394 installs address range
mappings on the default ioctl fd, i.e. a file that represents a random
device on the chosen port.  It receives incoming requests from any
sender node via this address range mapping.  Due to a kernel ABI
limitation, the sender node ID is not known though.  So far libraw1394
simply assumed the node ID of the device that provided the default
ioctl fd.  This only works if there is only one accessible fd on the
entire bus.

This limitation caused for example libffado to fail to work with
another AV/C or IIDC device attached to the bus, because node IDs of
FCP requests and FCP responses did not match since the latter were
wrong.  FCP clients which did not check sender node IDs were seemingly
not affected by this bug.  The bug is fixed by a kernel ABI extension
in Linux 2.6.36.  This libraw1394 change implements libraw1394's
counterpart to this ABI extension.

Hence this libraw1394 fix requires
  - kernel-headers 2.6.36 or later at build time of libraw1394
  - kernel 2.6.36 or later at runtime.
Otherwise, libraw1394 simply degrades to the faulty previous behaviour.

Side note:  The change of IMPLEMENTED_CDEV_ABI_VERSION to 4 requires
that we fill in struct fw_cdev_allocate.region_end which was added in
the ABI v4.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

0 files changed, 0 insertions, 0 deletions