linux_dsm_epyc7002/Documentation/ABI/removed/video1394
Stefan Richter 66fa12c571 ieee1394: remove the old IEEE 1394 driver stack
The drivers
  - ohci1394 (controller driver)
  - ieee1394 (core)
  - dv1394, raw1394, video1394 (userspace ABI)
  - eth1394, sbp2 (protocol drivers)
are replaced by
  - firewire-ohci (controller driver)
  - firewire-core (core and userspace ABI)
  - firewire-net, firewire-sbp2 (protocol drivers)
which are more featureful, better performing, and more secure than the older
drivers; all with a smaller and more modern code base.

The driver firedtv in drivers/media/dvb/firewire/ contains backends to both
ieee1394 and firewire-core.  Its ieee1394 backend code can be removed in an
independent commit; firedtv as-is builds and works fine without ieee1394.

The driver pcilynx (an incomplete controller driver) is deleted without
replacement since PCILynx cards are extremely rare.  Owners of these cards
use them with the stand-alone bus sniffer driver nosy instead.

The drivers nosy and init_ohci1394_dma which do not interact with either of
the two IEEE 1394 stacks are not affected by the ieee1394 subsystem removal.

There are still some issues with the newer firewire subsystem compared to
the older one:
  - The rare and quirky controllers ALi M52xx, Apple UniNorth v1, NVIDIA
    NForce2 are even less well supported by firewire-ohci than by ohci1394.
    I am looking into the M52xx issue.
  - The experimental firewire-net is reportedly less stable than its
    experimental cousin eth1394.
  - Audio playback of a certain group of audio devices (ones based on DICE
    chipset with EAP; supported by prerelease FFADO code) does not work yet.
    This issue is still under investigation.
  - There were some ieee1394 based out-of-the-mainline drivers.  Of them,
    only lisight, an audio driver for iSight webcams, seems still useful.
    Work is underway to reimplement it on top of firewire-core.

All these remainig issues are minor; they should not stand in the way of
overall better user experience of IEEE 1394 on Linux, together with a
reduction in support efforts and maintenance burden.  The coexistence of two
IEEE 1394 kernel driver stacks in the mainline since 2.6.22 shall end now,
as announced earlier this year.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-10-11 14:48:03 +02:00

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What: video1394 (a.k.a. "OHCI-1394 Video support" for FireWire)
Date: May 2010 (scheduled), finally removed in kernel v2.6.37
Contact: linux1394-devel@lists.sourceforge.net
Description:
/dev/video1394/* were character device files, one for each FireWire
controller, which were used for isochronous I/O. It was added as an
alternative to raw1394's isochronous I/O functionality which had
performance issues in its first generation. Any video1394 user had
to use raw1394 + libraw1394 too because video1394 did not provide
asynchronous I/O for device discovery and configuration.
Replaced by /dev/fw*, i.e. the <linux/firewire-cdev.h> ABI of
firewire-core.
Users:
libdc1394 (works with firewire-cdev too, transparent to library ABI
users)