Linux' IEEE 1394/ FireWire subsystem TODO list

[Stefan Richter]

Hi lists,

I copied the ancient linux1394 project TODO list from the static page at
www.linux1394.org over to http://wiki.linux1394.org/ToDo and
substantially updated it now.  I certainly missed a few important TODOs
and ideas, but the list is quite long nevertheless.  I thought of
posting a FireWire driver status report to LKML recently --- so I am
simply posting the TODO list now.  Another page related to FireWire
driver development status is http://wiki.linux1394.org/JujuMigration .

Reply or edit the wiki if you have additions or disagree with a TODO
item.  AFAIK wiki.linux1394.org does not require registration for
editing.


  Linux1394 Project TODO List

See our list of bugs
<http://bugzilla.kernel.org/buglist.cgi?product=Drivers&component=IEEE1394&bug_status=NEW&bug_status=ASSIGNED&bug_status=DEFERRED&bug_status=NEEDINFO>
at bugzilla.kernel.org. There are also bugs filed in distributors' bug
trackers but they are not as easy to query.

Contents

  IEEE1394 Subsystem (a.k.a. Linux1394 driver stack)
    * subsystem and core driver
    * sbp2
    * ether1394
    * raw1394
  FireWire subsystem (a.k.a. Juju driver stack)
    * support in userspace
    * subsystem and core driver
    * firewire-ohci
    * firewire-sbp2

------------------------------------------------------------------------


IEEE1394 Subsystem (a.k.a. Linux1394 driver stack)


  subsystem and core driver

    * Bug 8403 <http://bugzilla.kernel.org/show_bug.cgi?id=8403>: If
      several Linux boxes are plugged into the same bus, they may go
      multiple forced bus resets, fighting over who gets to be IRM. Our
      IRM code is too pessimistic if errors happen when querying the
      remote IRM for its capabilities.

    * Handle same node being connected to multiple local hosts
      (multi-pathing). 


  sbp2

    * Bug 1872 <http://bugzilla.kernel.org/show_bug.cgi?id=1872>: Fix
      serialize_io=0.

    * Implement per-node queueing options.
    
  Also see sbp2's TODO list in the source
  <http://lxr.linux.no/source/drivers/ieee1394/sbp2.c#L38>.


  ether1394

    * Improve reliability (bug 8361
      <http://bugzilla.kernel.org/show_bug.cgi?id=8361>, bug 8704
      <http://bugzilla.kernel.org/show_bug.cgi?id=8704>). Fix "Waking
      dma ctx=0 ... processing is probably too slow", perhaps by
      increasing the AR DMA buffer size in ohci1394.

    * Implement MCAP and multicast support. 


  raw1394

    * Bug 4779 <http://bugzilla.kernel.org/show_bug.cgi?id=4779>: Test
      and fix 32bit userland on 64bit kernel. It appears that only
      address range mapping is still buggy as of Linux 2.6.23.

    * Implement access to RAW1394_REQ_MODIFY_ROM in libraw1394. This
      should be used instead of RAW1394_REQ_UPDATE_ROM. Make sure that
      the RAW1394_REQ_MODIFY_ROM accessor can be ported to the ROM
      manipulation ioctl of the new firewire-core ABI, which should
      eventually be fully supported by libraw1394 too. 

------------------------------------------------------------------------


FireWire subsystem (a.k.a. Juju driver stack)


  support in userspace

    * Finish support by libraw1394.

    * Add support in libdc1394 v1?

    * Add support in FFmpeg's libavformat. 


  subsystem and core driver

    * Replace fw_notify() and fw_error() (defined in
      drivers/firewire/fw-transaction.h) by dev_notice() and dev_err()
      (defined in include/linux/device.h).

    * Implement IPv4 over FireWire as per RFC 2734, i.e. port the
      functionality of eth1394 to the new driver stack. But try not to
      port eth1394's bugs too.

    * Add IPv6 support as per RFC 3146.

    * Implement an SBP-2 target using the in-kernel SCSI target
      framework as an alternative to Endpoint (Oracle's SBP-2 target
      implementation in userspace). 


  firewire-ohci

    * Implement isochronous I/O for OHCI 1.0 compliant chips (such as
      VIA VT6306 and chips from NEC and Ricoh which are not OHCI 1.1
      compliant). That is, implement a mode which does not require
      dual-buffer IR DMA.

    * Bug 8828 <http://bugzilla.kernel.org/show_bug.cgi?id=8828>: Come
      up with a quirk fix for NForce2. The person to do so will most
      certainly require direct access to this hardware. Note, the
      NForce2 workaround in ohci1394 is unacceptable by today's
      standards as it involves busy-waiting in the interrupt handler.
      Either we find something better for firewire-ohci, or NForce2
      remains unsupported in firewire-ohci.

    * Quirk fix for old Apple UniNorth adapters?

    * There seem to be issues with ALi controllers. 


  firewire-sbp2

    * Eliminate calls to fw_memcpy_to_be32() by directly writing in big
      endian into struct fields of ORBs etc..

    * Fix remaining device recognition bugs. Best done in hands-on mode
      rather than via e-mail debugging.

    * Implement hand-over from OpenFirmware login. When an Apple PC
      boots from a FireWire disk, the OpenFirmware is already logged in
      but does apparently not log out after it loaded the kernel image.
      When then the kernel's firewire-sbp2 (or sbp2, for that matter)
      logs in, the target may deny access. This has been observed with
      Momobay CX-1. The old ieee1394 driver stack somehow overcomes this
      because of timing subtleties, but firewire-sbp2 ends up with
      failed login due to denied access.

    * Implement dynamically appended ORB lists for performance
      improvement. Note, the old sbp2 driver's implementation of ORB
      lists is very buggy and does not seem to improve performance
      noticeably.

    * Implement SBP-3 FASTSTART protocol which is rumored to be
      supported by newer OxSemi bridges.

    * Bug 3225 <http://bugzilla.kernel.org/show_bug.cgi?id=3225>:
      Integrate with scsi_wait_scan module?


PS: It seems also appropriate to disclose the current manpower behind
FireWire driver development and maintenance.  There are just two people
who regularly work on the drivers:  Kristian Høgsberg (author and
maintainer of the new firewire subsystem, in the past also involved with
the old ieee1394 subsystem) and me (co-maintainer of both the new and
old subsystems).  But we both have a lot of other projects going on at
the moment.
-- 
Stefan Richter
-=====-=-=== =--= -=---
http://arcgraph.de/sr/

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