This fixes a regression by "firewire: keep highlevel drivers attached
during brief connection loss":  There were 2 seconds unnecessary waiting
added to the shutdown procedure of each controller.

We use card->link as status flag to signal the device handler that there
is no use to wait for a come-back.

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

There are situations when nodes vanish from the bus and come back
quickly thereafter:
  - When certain bus-powered hubs are plugged in,
  - when certain devices are plugged into 6-port hubs,
  - 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.

Until now, firewire-core reported affected nodes as lost to the
highlevel drivers (firewire-sbp2 and userspace drivers).  We now delay
the destruction of device representations until after at least two
seconds after the last bus reset.  If a "new" device is detected in this
period whose bus information block and root directory header match that
of a device which is pending for deletion, we resurrect that device and
send update calls to highlevel drivers.

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

Due to commit 2831fe6f9cc4e16c103504ee09a47a084297c0f3, "driver core:
create a private portion of struct device", device_initialize() can no
longer be called from atomic contexts.

We now defer it until after config ROM probing.  This requires changes
to the bus manager code because this may use a device before it was
probed.

Reported-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Take a reference to the card whenever fw_card_bm_work() is scheduled on
that card and release it when the work is done.  This allows us to
remove the cancel_delayed_work_sync() in fw_core_remove_card().

Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (patch update)

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

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Share code between fw_send_request + wait_for_completion callers.

Signed-off-by: Jay Fenlason <fenlason@redhat.com>

Addendum:
Removes an unnecessary struct and an ununsed retry loop.
Calls it fw_run_transaction() instead of fw_send_request_sync().

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Kristian Høgsberg <krh@redhat.com>

This is a functionally equivalent replacement of the current reference
counting of struct fw_card instances.  It only converts it to common
idioms as suggested by Kristian Høgsberg:
  - struct kref replaces atomic_t as the counter.
  - wait_for_completion is used to wait for all card users to complete.

BTW, it may make sense to count card->flush_timer and card->work as
card users too.

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

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

Trivial change to replace more meaningless (to the untrained eye) hex
values with defined CSR constants.

Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>