Re: [PATCH] firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

> Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check
> whether the current IRM complies to 1394a-2000 or later.  If not force a
> compliant node (e.g. itself) to become IRM.  This was implemented in the
> older ieee1394 driver but not yet in firewire-core.

While I don't have an IRM that features the DCR-TRV25 bug, I did at
least quick tests of the patch with the following consistent results:
  - Joined three nodes to a bus, only one node of them IRM capable,
    but being a 1394-1995-only implementation.
  - Plugged in Linux node into this bus, got the following log:
        firewire_ohci: isochronous cycle inconsistent
        firewire_core: created device fw8: GUID 00d04b21010212c8, S400
        firewire_core: created device fw9: GUID 008088030960484b, S100
        firewire_core: phy config: card 4, new root=ffc3, gap_count=7
        firewire_core: IRM is not 1394a compliant, making local node (ffc1) root.
        firewire_core: phy config: card 4, new root=ffc1, gap_count=7
    and all is well as far as kernel, gscanbus, and Kino can tell.
-- 
Stefan Richter
-=====-==-=- -=-= ====-
http://arcgraph.de/sr/