read_rom() obtained a fresh new fw_device.generation for each read
transaction.  Hence it was able to continue reading in the middle of the
ROM even if a bus reset happened.  However the device may have modified
the ROM during the reset.  We would end up with a corrupt fetched ROM
image then.

Although all of this is quite unlikely, it is not impossible.
Therefore we now restart reading the ROM if the bus generation changed.

Note, the memory barrier in read_rom() is still necessary according to
tests by Jarod Wilson, despite of the ->generation access being moved up
in the call chain.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This is essentially what I've been beating on locally, and I've yet to hit
another config rom read failure with it.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

fw_device.node_id and fw_device.generation are accessed without mutexes.
We have to ensure that all readers will get to see node_id updates
before generation updates.

Fixes an inability to recognize devices after "giving up on config rom",
https://bugzilla.redhat.com/show_bug.cgi?id=429950Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Reviewed by Nick Piggin <nickpiggin@yahoo.com.au>.

Verified to fix 'giving up on config rom' issues on multiple system and
drive combinations that were previously affected.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>

We have to use the fw_device.generation here, not the fw_card.generation,
because the generation must never be newer than the node ID when we emit
a transaction.  This cannot be guaranteed with fw_card.generation.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Verified in concert with subsequent memory barriers patch to fix 'giving
up on config rom' issues on multiple system and drive combinations that
were previously affected.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

There was a small window where a login or reconnect job could use an
already updated card generation with an outdated node ID.  We have to
use the fw_device.generation here, not the fw_card.generation, because
the generation must never be newer than the node ID when we emit a
transaction.  This cannot be guaranteed with fw_card.generation.

Furthermore, the target's and initiator's node IDs can be obtained from
fw_device and fw_card.  Dereferencing their underlying topology objects
is not necessary.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Verified in concert with subsequent memory barriers patch to fix 'giving
up on config rom' issues on multiple system and drive combinations that
were previously affected.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

Ask the target to grant 4 seconds instead of the standard and minimum of
1 second window after bus reset for reconnection.  This accelerates
reconnection if there are more than one targets on the bus:  If a login
and inquiry to one target blocks the fw-sbp2 workqueue for more than 1s
after bus reset, we now still can reconnect to the other target.

Before that, fw-sbp2's reconnect attempts would be rejected with "error
status: 0:9" (function rejected), and fw-sbp2 would finally re-login.
All those futile reconnect attemps cost extra time until the target
which needs re-login is ready for I/O again.

The reconnect timeout field in the login ORB doesn't have to be honored
by the target though.  I found that we could get up to
  - allegedly 32768s from an old OXFW911 firmware
  - 256s from LSI bridges
  - 4s from OXUF922 and OXFW912 bridges,
  - 2s from TI bridges,
  - only the standard 1s from Initio and Prolific bridges and from
    Apple OpenFirmware in target mode.

We just try to get 4 seconds which already covers the case of a few
HDDs on the same bus quite nicely.

A minor drawback occurs in the following (rare and impractical) border
case:
  - two initiators are there, initiator 1 holds an exclusive login to
    a target,
  - initiator 1 goes off the bus,
  - target refuses login attempts from initiator 2 until reconnect_hold
    seconds after bus reset.

An alternative approach to the issue at hand would be to parallelize
fw-sbp2's reconnect and login work.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: NJarod Wilson <jwilson@redhat.com>

Don't attempt to send a logout ORB if the target was already unplugged
or had its link switched off.  If two targets are attached, this
enhances the chance to quickly reconnect to the remaining target when
one target is plugged out.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: NJarod Wilson <jwilson@redhat.com>

Previously, the fw-ohci driver used fixed-length buffers for storing
descriptors for isochronous receive DMA programs.  If an application
(such as libdc1394) generated a DMA program that was too large, fw-ohci
would reach the limit of its fixed-sized buffer and return an error to
userspace.

This patch replaces the fixed-length ring-buffer with a linked-list of
page-sized buffers.  Additional buffers can be dynamically allocated and
appended to the list when necessary.  For a particular context, buffers
are kept around after use and reused as necessary, so there is no
allocation taking place after the DMA program is generated for the first
time.

In addition, the buffers it uses are coherent for DMA so there is no
syncing required before and after writes.  This syncing wasn't properly
done in the previous version of the code.

-

This is the fourth version of my patch that replaces a fixed-length
buffer for DMA descriptors with a dynamically allocated linked-list of
buffers.

As we discovered with the last attempt, new context programs are
sometimes queued from interrupt context, making it unacceptable to call
tasklet_disable() from context_get_descriptors().

This version of the patch uses ohci->lock for all locking needs instead
of tasklet_disable/enable.  There is a new requirement that
context_get_descriptors() be called while holding ohci->lock.  It was
already held for the AT context, so adding the requirement for the iso
context did not seem particularly onerous.  In addition, this has the
side benefit of allowing iso queue to be safely called from concurrent
user-space threads, which previously was not safe.
Signed-off-by: NDavid Moore <dcm@acm.org>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

-

Fixes the following issues:
  - Isochronous reception stopped prematurely if an application used a
    larger buffer.  (Reproduced with coriander.)
  - Isochronous reception stopped after one or a few frames on VT630x
    in OHCI 1.0 mode.  (Fixes reception in coriander, but dvgrab still
    doesn't work with these chips.)

Patch update: struct member alignment, whitespace nits
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The firewire-ohci driver so far lacked the ability to resume cycle
master duty after that condition happened, as added to ohci1394 in Linux
2.6.18 by commit 57fdb58f.  This ports
this patch to fw-ohci.

The "cycle too long" condition has been seen in practice
  - with IIDC cameras if a mode with packets too large for a speed is
    chosen,
  - sporadically when capturing DV on a VIA VT6306 card with ohci1394/
    ieee1394/ raw1394/ dvgrab 2.
    https://bugzilla.redhat.com/show_bug.cgi?id=415841#c7
(This does not fix Fedora bug 415841.)
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Fix extraction of the source node id from the packet header.
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch corrects a number of bugs in the current OHCI 1.0
packet-per-buffer support:

1. Correctly deal with payloads that cross a page boundary.  The
previous version would not split the descriptor at such a boundary,
potentially corrupting unrelated memory.

2. Allow user-space to specify multiple packets per struct
fw_cdev_iso_packet in the same way that dual-buffer allows.  This is
signaled by header_length being a multiple of header_size.  This
multiple determines the number of packets.  The payload size allocated
per packet is determined by dividing the total payload size by the
number of packets.

3. Make sync support work properly for packet-per-buffer.

I have tested this patch with libdc1394 by forcing my OHCI 1.1
controller to use the packet-per-buffer support instead of dual-buffer.

I would greatly appreciate testing by those who have a DV devices and
other types of iso streamers to make sure I didn't cause any
regressions.

Stefan, with this patch, I'm hoping that libdc1394 will work with all
your OHCI 1.0 controllers now.

The one bit of future work that remains for packet-per-buffer support is
the automatic compaction of short payloads that I discussed with
Kristian.
Signed-off-by: NDavid Moore <dcm@acm.org>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch fixes the problem where different OHCI 1.1 controllers behave
differently when a received iso packet straddles three or more buffers
when using the dual-buffer receive mode.  Two changes are made in order
to handle this situation:

1. The packet sync DMA descriptor is given a non-zero header length and
non-zero payload length.  This is because zero-payload descriptors are
not discussed in the OHCI 1.1 specs and their behavior is thus
undefined.  Instead we use a header size just large enough for a single
header and a payload length of 4 bytes for this first descriptor.

2. As we process received packets in the context's tasklet, read the
packet length out of the headers.  Keep track of the running total of
the packet length as "excess_bytes", so we can ignore any descriptors
where no packet starts or ends.  These descriptors may not have had
their first_res_count or second_res_count fields updated by the
controller so we cannot rely on those values.

The main drawback of this patch is that the excess_bytes value might get
"out of sync" with the packet descriptors if something strange happens
to the DMA program.  I'm not if such a thing could ever happen, but I
appreciate any suggestions in making it more robust.

Also, the packet-per-buffer support may need a similar fix to deal with
issue 1, but I haven't done any work on that yet.

Stefan, I'm hoping that with this patch, all your OHCI 1.1 controllers
will work properly with an unmodified version of libdc1394.
Signed-off-by: NDavid Moore <dcm@acm.org>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

SBP2_MAX_SECTORS is nowhere used in fw-sbp2.
It merely got copied over from sbp2 where it played a role in the past.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

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

This somewhat reduces the size of firewire-sbp2.ko.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch relaxes the default SCSI DMA alignment from 512 bytes to 4
bytes.  I remember from previous discussions that usb and firewire have
sector size alignment requirements, so I upped their alignments in the
respective slave allocs.

The reason for doing this is so that we don't get such a huge amount of
copy overhead in bio_copy_user() for udev.  (basically all inquiries it
issues can now be directly mapped).
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Third rendition of FireWire OHCI 1.0 Isochronous Receive support, using a
zer-copy method similar to OHCI 1.1 which puts the IR data payload directly
into the userspace buffer. The zero-copy implementation eliminates the
video artifacts, audio popping, and buffer underrun problems seen with
version 1 of this patch, as well as fixing a regression in OHCI 1.1 support
introduced by version 2 of this patch.

Successfully tested in OHCI 1.1 mode on the following chipsets:

- NEC uPD72847 (rev 01), OHCI 1.1 (PCI)
- Ti XIO2200(A) (rev 01), OHCI 1.1 (PCIe)
- Ti TSB41AB2 (rev 01), OHCI 1.1 (PCI on SB Audigy)
- Apple UniNorth 2 (rev 81), OHCI 1.1 (PowerBook G4 onboard)

Successfully tested in OHCI 1.0 mode on the following chipsets:

- Agere FW323 (rev 06), OHCI 1.0 (Mac Mini onboard)
- Agere FW323 (rev 06), OHCI 1.0 (PCI)
- Via VT6306 (rev 46), OHCI 1.0 (PCI)
- NEC OrangeLink (rev 01), OHCI 1.0 (PCI)
- NEC uPD72847 (rev 01), OHCI 1.1 (PCI)
- Ti XIO2200(A) (rev 01), OHCI 1.1 (PCIe)

The bulk of testing was done in an x86_64 system, but was also successfully
sanity-tested on other systems, including a PPC(32) PowerBook G4 and an i686
EPIA M10k. Crude benchmarking (watching top during capture) puts the cpu
utilization during capture on the EPIA's 1GHz Via C3 processor around 13%,
which is down from 30% with the v1 code.

Some implementation details:

To maintain the same userspace API as dual-buffer mode, we set up two
descriptors for every incoming packet. The first is an INPUT_MORE descriptor,
pointing to a buffer large enough to hold just the packet's iso headers,
immediately followed by an INPUT_LAST descriptor, pointing to a chunk of the
userspace buffer big enough for the packet's data payload. With this setup,
each incoming packet fills in these two descriptors in a manner that very
closely emulates dual-buffer receive, to the point where the bulk of the
handle_ir_* code is now identical between the two (and probably primed for
some restructuring to share code between them).

The only caveat I have at the moment is that neither of my OHCI 1.0 Via
VT6307-based FireWire controllers work particularly well with this code
for reasons I have yet to figure out.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Since patch "fw-sbp2: use an own workqueue (fix system responsiveness)"
increased parallelism between fw-sbp2 and fw-core, it was possible that
fw-sbp2 didn't release the SCSI device when the FireWire device was
disconnected.

This happened if sbp2_update() ran during sbp2_login(), because a bus
reset occurred during sbp2_login().  The sbp2_login() work would [try
to] reschedule itself because it failed due to the bus reset, and it
would _not_ drop its reference on the target.  However, sbp2_update()
would schedule sbp2_login() too before sbp2_login() rescheduled itself
and hence sbp2_update() would take an additional reference.  And then
we would have one reference too many.

The fix is to _always_ drop the reference when leaving the sbp2_login()
work.  If the sbp2_login() work reschedules itself, it takes a
reference, but only if it wasn't already rescheduled by sbp2_update().

Ditto in the sbp2_reconnect() work.

The resulting code is actually simpler than before:  We _always_ take
a reference when successfully scheduling work.  And we _always_ drop
a reference when leaving a workqueue job.  No exceptions.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The ohci_enable() function shared between pci_probe and pci_resume
takes a host endian config rom, but ohci->config_rom is __be32.  This
sets up the config rom in the wrong endian on little endian machine,
specifically, BusOptions will be initialized to a 0 max receive size.

This patch changes the way we reuse the config rom so that we avoid
this problem.
Signed-off-by: NKristian Hoegsberg <krh@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

New warning since commit ab88ca48,
"firewire: fw-ohci: missing dma_unmap_single":
drivers/firewire/fw-ohci.c: In function 'at_context_transmit':
drivers/firewire/fw-ohci.c:609: warning: 'payload_bus' may be used
 uninitialized in this function

Access to payload_bus is conditional on packet->payload_length > 0,
and that won't change while in at_context_queue_packet.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

because there seems to be more time needed to implement this.
Also, change related error return values to more appropriate ones.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

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

Prompted by https://bugzilla.redhat.com/show_bug.cgi?id=323411Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NYann Dirson <ydirson@altern.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (update)

fw_node() is not used (and not useful) outside fw-topology.c.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This duplicates the read cycle timer feature of raw1394 (added in Linux
2.6.21) in firewire-core's userspace ABI.  The argument to the ioctl is
reordered though to ensure 32/64 bit compatibility.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>

Check NodeID.nodeNumber as per OHCI 1.1 clause 7.2.3.2.  See also IEEE
1394a table 5B-1.

Also, demote the "node ID not valid" message from error to notification
as it is not an error condition.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

at_context_queue_packet() didn't clean up in an early exit path.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>

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

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

Add used includes, remove unused includes.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

It seems unlikely, but access to self_id_cpu[0] could at least in theory
be deferred until after the loop over self_id_cpu[1..n] or even after
the subsequent reg_read.  Enforce the desired order by a read barrier.

Also prevent the reg_read from being reordered relative to the for loop.
This isn't necessary if the loop's conditional printk counts as an
implicit barrier, but better make it explicit.

(self_id_cpu[] is a coherent DMA buffer.)
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Firewire-sbp2 did very uncooperative things in the kernel's shared
workqueue:  Sleeping until reception of management status from the
target for up to 2 seconds, and performing SCSI inquiry and all of the
setup of SCSI command set drivers via scsi_add_device.  If there were
transient or permanent error conditions, this caused long blockage of
the kernel's events process, noticeable e.g. by blocked keyboard input.

We now allocate a workqueue process exclusive to fw-sbp2.  As a side
effect, this also increases parallelism of fw-sbp2's login and reconnect
work versus fw-core's device discovery and device update work which is
performed in the shared workqueue.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>

On rare occasions, the ability to set one of the workaround flags at
runtime may save the day.

People who experience I/O errors with firewire-sbp2 while the old sbp2
driver worked for them should try workarounds=1 and report to the devel
mailinglist whether that improves things.  Firewire-sbp2 defaults to the
SCSI stack's maximum transfer size per command, while sbp2 limits them
to 128 kBytes.  Flag 1 accomplishes just that.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Fixes "New firewire stack only recognizing half of a chain of drives",
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=242254Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

On IOMMU-less noncoherent architectures, orb->callback will memcpy the
whole SCSI command buffer for READ-like SCSI commands.  It is therefore
friendlier to enable IRQs before the call, like before patch "Add
ref-counting for sbp2 orbs".
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: NKristian Høgsberg <krh@redhat.com>

Sparse warned about it although it was apparently harmless:

drivers/firewire/fw-cdev.c:624:23: warning: symbol 'interrupt' shadows an earlier one
include/asm/hw_irq.h:29:13: originally declared here
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Potentially avoids unnecessary loop runs.
Guarantee quadlet-aligned starts of address regions.
Document the return values.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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