linux/drivers/ieee1394
Stefan Richter fc392fe831 ieee1394: survive a few seconds connection loss
There are situations when nodes vanish from the bus and come back in
quickly thereafter:
  - When certain bus-powered hubs are plugged in,
  - when certain disk enclosures are switched from self-power to bus
    power or vice versa and break the daisy chain during the transition,
  - when the user plugs a cable out and quickly plugs it back in, e.g.
    to reorder a daisy chain (works on Mac OS X if done quickly enough),
  - when certain hubs temporarily malfunction during high bus traffic.

The ieee1394 driver's nodemgr already contained a function to set
vanished nodes aside into "limbo"; i.e. they wouldn't actually be
deleted right away.  (In fact, only unloading the driver or writing into
an obscure sysfs attribute would delete them eventually.)  If nodes
reappeared later, they would be resurrected out of limbo.

Moving nodes into and out of limbo was accompanied with calling the
.suspend() and .resume() driver methods of the drivers which were bound
to a respective node's unit directories.  Not only is this somewhat
strange due to the intended use of these driver methods for power
management, also the sbp2 driver in particular does not implement
.suspend() and .resume().  Hence sbp2 would be disconnected from devices
in situations as listed above.

We now:
  - leave drivers bound when nodes go into limbo,
  - call the drivers' .update() when nodes come out of limbo,
  - automatically delete in-limbo nodes 3 seconds after the last
    bus reset and bus rescan.
  - Because of the automatic removal, the now obsolete bus attribute
    /sys/bus/ieee1394/destroy_node is removed.

This especially lets sbp2 survive brief disconnections.  You can for
example yank a disk's cable and plug it back in while reading the
respective disk with dd, but dd will happily continue as if nothing
happened.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-10-15 22:21:09 +02:00
..
config_roms.c ieee1394: eth1394: don't autoload by hotplug when ohci1394 starts 2007-04-30 00:00:30 +02:00
config_roms.h ieee1394: eth1394: don't autoload by hotplug when ohci1394 starts 2007-04-30 00:00:30 +02:00
csr1212.c ieee1394: Use DIV_ROUND_UP 2008-10-15 22:21:07 +02:00
csr1212.h ieee1394: csr1212: proper refcounting 2007-10-16 23:59:59 +02:00
csr.c ieee1394: be*_add_cpu conversion 2008-04-18 17:55:29 +02:00
csr.h [PATCH] ieee1394: clean up declarations of hpsb_*_config_rom 2006-07-03 12:02:31 -04:00
dma.c ieee1394: dump mmapped iso buffers in core files 2008-07-14 13:06:02 +02:00
dma.h ieee1394: move some comments from declaration to definition 2007-04-30 00:00:28 +02:00
dv1394-private.h [PATCH] ieee1394: dv1394: sem2mutex conversion 2006-07-03 12:02:32 -04:00
dv1394.c ieee1394: dv1394, video1394: remove unnecessary expressions 2008-10-15 22:21:09 +02:00
dv1394.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
eth1394.c ieee1394: Use DIV_ROUND_UP 2008-10-15 22:21:07 +02:00
eth1394.h ieee1394: eth1394: handle tlabel exhaustion 2007-05-27 23:20:59 +02:00
highlevel.c ieee1394: video1394: reorder module init, prepare BKL removal 2008-07-14 13:06:02 +02:00
highlevel.h ieee1394: video1394: reorder module init, prepare BKL removal 2008-07-14 13:06:02 +02:00
hosts.c ieee1394: first minimal NUMA awareness 2007-07-10 00:07:40 +02:00
hosts.h ieee1394: remove old isochronous ABI 2007-07-10 00:07:41 +02:00
ieee1394_core.c ieee1394: limit early node speed to host interface speed 2008-04-18 17:55:31 +02:00
ieee1394_core.h ieee1394: remove old isochronous ABI 2007-07-10 00:07:41 +02:00
ieee1394_hotplug.h [PATCH] ieee1394: remove redundant code from ieee1394_hotplug.h 2006-07-03 12:02:30 -04:00
ieee1394_transactions.c ieee1394: remove unused code 2008-01-30 22:22:20 +01:00
ieee1394_transactions.h ieee1394: remove old isochronous ABI 2007-07-10 00:07:41 +02:00
ieee1394_types.h ieee1394: safer definition of empty macros 2006-09-17 19:31:20 +02:00
ieee1394-ioctl.h ieee1394: cycle timer read extension for raw1394 2007-02-17 14:39:33 +01:00
ieee1394.h [PATCH] ieee1394: coding style and comment fixes in midlayer header files 2006-07-03 12:02:28 -04:00
init_ohci1394_dma.c x86: early boot debugging via FireWire (ohci1394_dma=early) 2008-01-30 13:34:11 +01:00
iso.c PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
iso.h ieee1394: rawiso: requeue packet for transmission after skipped cycle 2008-04-25 18:15:45 +02:00
Kconfig ieee1394: Kconfig menu touch-up 2008-06-19 00:12:36 +02:00
Makefile x86: early boot debugging via FireWire (ohci1394_dma=early) 2008-01-30 13:34:11 +01:00
nodemgr.c ieee1394: survive a few seconds connection loss 2008-10-15 22:21:09 +02:00
nodemgr.h ieee1394: survive a few seconds connection loss 2008-10-15 22:21:09 +02:00
ohci1394.c ieee1394: rawiso: requeue packet for transmission after skipped cycle 2008-04-25 18:15:45 +02:00
ohci1394.h ieee1394: remove old isochronous ABI 2007-07-10 00:07:41 +02:00
pcilynx.c ieee1394: Use shorter list_splice_init() for brevity. 2008-04-18 17:55:30 +02:00
pcilynx.h Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
raw1394-private.h ieee1394: raw1394: replace BKL by local mutex, make ioctl() and mmap() thread-safe 2008-10-15 22:21:08 +02:00
raw1394.c ieee1394: raw1394: make write() thread-safe 2008-10-15 22:21:08 +02:00
raw1394.h ieee1394: remove old isochronous ABI 2007-07-10 00:07:41 +02:00
sbp2.c ieee1394: sbp2: enforce s/g segment size limit 2008-10-15 22:21:07 +02:00
sbp2.h ieee1394: sbp2: enforce s/g segment size limit 2008-10-15 22:21:07 +02:00
video1394.c ieee1394: dv1394, video1394: remove unnecessary expressions 2008-10-15 22:21:09 +02:00
video1394.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00