This is a minimal change meant for the short term:  Never set the
ohci->use_dualbuffer flag to true.

There are two reasons to do so:

  - Packet-per-buffer mode and dual-buffer mode do not behave the same
    under certain circumstances, notably if several packets are covered
    by a single fw_cdev_iso_packet descriptor.
    http://marc.info/?l=linux1394-devel&m=124965653718313
    Therefore the driver stack should not silently choose one or the
    other mode but should leave the choice to the high-level driver
    (regardless if kernel driver or userspace driver).  Or simply always
    only offer packet-per-buffer mode, since a considerable number of
    controllers, even current ones, does not offer dual-buffer support.

  - Even under circumstances where packet-per-buffer mode and
    dual-buffer mode behave exactly the same --- notably when used
    through libraw1394, libdc1394, as well as the current two kernel
    drivers which use isochronous reception (firewire-net and firedtv)
    --- we are still faced with the problem that several OHCI 1.1
    controllers have bugs in dual-buffer mode.  Although it looks like
    we have identified most of those buggy controllers by now, we
    cannot be quite sure about that.

So, use packet-per-buffer by default from now on.  This change should
be followed up by a more complete solution:  Either extend the
in-kernel API and the userspace ABI by a choice between the two IR modes
or remove all dual-buffer related code from firewire-ohci.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Queueing to receive an ISO packet with a payload length of zero
silently does nothing in dualbuffer mode, and crashes the kernel in
packet-per-buffer mode.  Return an error in dualbuffer mode, because
the DMA controller won't let us do what we want, and work correctly in
packet-per-buffer mode.
Signed-off-by: NJay Fenlason <fenlason@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Cc: stable@kernel.org

Here is the final set of patches I used to get ffado to work with the
new firewire stack.  With these patches, I was able to start ardour
and record from and playback to my PreSonus Inspire1394 from a
(mostly) Fedora 12 system.
Signed-off-by: NJay Fenlason <fenlason@redhat.com>

Until now, firewire-ohci exposed only the transmit cycle of the last
transmitted packet at each isochronous transmit complete event.  This
made it impossible for FFADO (FireWire audio drivers in userspace) to
synchronize audio-out streams.  The fix is to store the timestamp of
each packet in the iso xmit event.  As a bonus, the transfer status is
stored too.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Calling the START_ISO ioctl with a nonnegative cycle paramater has
never worked.  Last night I got around to figuring out why.  Most of
this patch is a big comment explaining why we enable an interrupt
source then don't actually do anything when we get one.  As the
comment says, we should do more, but we don't have a way to tell
userspace what happened. . .
Signed-off-by: NJay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (edited comment)

I was told that there are obscure architectures with non-coherent DMA
which may DMA-map to bus address 0.  We shall not use 0 as a magic
number of uninitialized bus address variables.

The packet->payload_length > 0 test cannot be used either (except in
at_context_queue_packet) because local requests are not DMA-mapped
regardless of payload_length.  Hence add a state flag to struct
fw_packet.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The config ROM image of the local node was created in CPU byte order,
then a temporary big endian copy was created to compute the CRC, and
finally the card driver created its own big endian copy.

We now generate it in big endian byte order in the first place to avoid
one byte order conversion and the temporary on-stack copy of the ROM
image (1000 bytes stack usage in process context).  Furthermore, two
1000 bytes memset()s are replaced by one 1000 bytes - ROM length sized
memset.

The trivial fw_memcpy_{from,to}_be32() helpers are now superfluous and
removed.  The newly added __compute_block_crc() function will be folded
into fw_compute_block_crc() in a subsequent change.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The selfIDSize field of Self ID Count is 9 bits wide, and we are only
interested in the high 8 bits.  Fix the mask accordingly.  The
previously too large mask didn't do damage though because the next few
bits in the register are reserved and therefore zero with presently
existing hardware.

Also, check for the maximum possible self ID count of 252 (according to
OHCI 1.1 clause 11.2 and IEEE 1394a-2000 clause 4.3.4.1, i.e. up to four
self IDs of up to 63 nodes, even though IEEE 1394 up to edition 2008
defines only up to three self IDs per node).  More than 252 self IDs
would only happen if the self ID receive DMA unit malfunctioned, which
would likely be caught by other self ID buffer checks.  However, check
it early to be sure.  More than 253 quadlets would overflow the Topology
Map CSR.

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

In dual-buffer DMA mode, no video frames are ever received from R5C832
by libdc1394.  Fallback to packet-per-buffer DMA works reliably.
http://thread.gmane.org/gmane.linux.kernel.firewire.devel/13393/focus=13476Reported-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

An Agere FW643 OHCI 1.1 card works fine for video reception from one
camera but fails early if receiving from two cameras.  After a short
while, no IR IRQ events occur and the context control register does not
react anymore.  This happens regardless whether both IR DMA contexts are
dual-buffer or one is dual-buffer and the other packet-per-buffer.

This can be worked around by disabling dual buffer DMA mode entirely.
http://sourceforge.net/mailarchive/message.php?msg_name=4A7C0594.2020208%40gmail.com
(Reported by Samuel Audet.)

In another report (by Jonathan Cameron), an FW643 works OK with two
cameras in dual buffer mode.  Whether this is due to different chip
revisions or different usage patterns (different video formats) is not
yet clear.  However, as far as the current capabilities of
firewire-core's isochronous I/O interface are concerned, simply
switching off dual-buffer on non-working and working FW643s alike is not
a problem in practice.  We only need to revisit this issue if we are
going to enhance the interface, e.g. so that applications can explicitly
choose modes.
Reported-by: NSamuel Audet <samuel.audet@gmail.com>
Reported-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The source files of firewire-core, firewire-ohci, firewire-sbp2, i.e.
 "drivers/firewire/fw-*.c"
are renamed to
 "drivers/firewire/core-*.c",
 "drivers/firewire/ohci.c",
 "drivers/firewire/sbp2.c".

The old fw- prefix was redundant to the directory name.  The new core-
prefix distinguishes the files according to which driver they belong to.

This change comes a little late, but still before further firewire
drivers are added as anticipated RSN.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The three header files of firewire-core, i.e.
 "drivers/firewire/fw-device.h",
 "drivers/firewire/fw-topology.h",
 "drivers/firewire/fw-transaction.h",
are replaced by
 "drivers/firewire/core.h",
 "include/linux/firewire.h".

The latter includes everything which a firewire high-level driver (like
firewire-sbp2) needs besides linux/firewire-constants.h, while core.h
contains the rest which is needed by firewire-core itself and by low-
level drivers (card drivers) like firewire-ohci.

High-level drivers can now also reside outside of drivers/firewire
without having to add drivers/firewire to the header file search path in
makefiles.  At least the firedtv driver will be such a driver.

I also considered to spread the contents of core.h over several files,
one for each .c file where the respective implementation resides.  But
it turned out that most core .c files will end up including most of the
core .h files.  Also, the combined core.h isn't unreasonably big, and it
will lose more of its contents to linux/firewire.h anyway soon when more
firewire drivers are added.  (IP-over-1394, firedtv, and there are plans
for one or two more.)

Furthermore, fw-ohci.h is renamed to ohci.h.  The name of core.h and
ohci.h is chosen with regard to name changes of the .c files in a
follow-up change.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Include required headers which were only indirectly included.
Remove unused includes and an unused constant.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

In the unlikely event that card->driver->get_bus_time() is called during
a cycle64Seconds interrupt, we could read garbage unless atomic accesses
are used.

The switch to atomic ops requires to change the 64 seconds counter from
unsigned to signed, but this shouldn't matter to the end result.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Allow userspace and other firewire drivers (fw-ipv4 I'm looking at
you!) to send Asynchronous Transmit Streams as described in 7.8.3 of
release 1.1 of the 1394 Open Host Controller Interface Specification.
Signed-off-by: NJay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (tweaks)

Standardize on  if (err)
                        handle_error;
           and  if (ret < 0)
                        handle_error;

Don't call a variable err if we store values in it which mean success.
Also, offset some return statements by a blank line since this how we do
it in drivers/firewire.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

OHCI-1394 1.1 clause 10.4.3 says:  "If more than one IR DMA context
specifies receives for packets from the same isochronous channel, the
context destination for that channel's packets is undefined."

Any userspace client and in the future also kernelspace clients can
allocate IR DMA contexts for any channel.  We don't want them to
interfere with each other, hence it is preferable to return -EBUSY if
allocation of a second context for a channel is attempted.

Notes:
  - This limitation is OHCI-1394 specific, therefore its proper place of
    implementation is down in the low-level driver.

  - Since the <linux/firewire-cdev.h> ABI simply maps one userspace iso
    client context to one hardware iso context, this OHCI-1394
    limitation alas requires userspace to implement its own multiplexing
    of iso reception from the same channel and card to multiple clients
    when needed.

  - The limitation is independent of channel allocation at the IRM; the
    latter is really only important for the initiation of iso 
    transmission but not of iso reception.

  - We don't need to do the same for IT DMA because OHCI-1394 does not
    have any ties between IT contexts and channels.  Only the voluntary
    channel allocation protocol via the IRM, globally to the FireWire
    bus, can ensure proper isochronous transmit behaviour anyway.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

type
    function_name(parameters);

is nice to look at but was not used consistently.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

"ret" is the new "retval".
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Previously, when an iso context had header_size > 4, the iso header
(len/tag/channel/tcode/sy) was passed to userspace followed by quadlets
stripped from the payload.  This patch changes the behavior:
header_size = 8 now passes the header quadlet followed by the timestamp
quadlet.  When header_size > 8, quadlets are stripped from the payload.
The header_size = 4 case remains identical.

Since this alters the semantics of the API, the firewire API version
needs to be bumped concurrently with this change.

This change also refactors the header copying code slightly to be much
easier to read.
Signed-off-by: NDavid Moore <dcm@acm.org>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Camcorders have a tendency to fail read requests to their config ROM and
write request to their FCP command register with ack_busy_X.  This has
become a problem with newer kernels and especially Panasonic camcorders,
causing AV/C in dvgrab and kino to fail.  Dvgrab for example frequently
logs "send oops"; kino reports loss of AV/C control.  I suspect that
lower CPU scheduling latencies in newer kernels made this issue more
prominent now.

According to
https://sourceforge.net/tracker/?func=detail&atid=114103&aid=2492640&group_id=14103
this can be fixed by configuring the FireWire controller for more
hardware retries for request transmission; these retries are evidently
more successful than libavc1394's own retry loop (typically 3 tries on
top of hardware retries).

Presumably the same issue has been reported at
https://bugzilla.redhat.com/show_bug.cgi?id=449252 and
https://bugzilla.redhat.com/show_bug.cgi?id=477279 .

In a quick test with a JVC camcorder (which didn't malfunction like the
reported camcorders), this change decreased the number of ack_busy_X
from 16 in three runs of dvgrab to 4 in three runs of the same capture
duration.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The present message is mostly just noise.  We only need to be notified
if the "active" flag does not go off before the retry loop terminates.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

There is a DMA map/ unmap imbalance whenever a block write request
packet is sent and then dequeued with ohci_cancel_packet.  The latter
may happen frequently if the AR resp tasklet is executed before the AT
req tasklet for the same transaction.

Add the missing dma_unmap_single.  This fixes
https://bugzilla.redhat.com/show_bug.cgi?id=475156

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

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

Fix leaks when pci_probe fails.  Simplify error log strings.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The transmit and receive context dma memory was not being freed on
module removal.  Neither was the config rom memory.  Fix that.

The ab->next assignment is pure paranoia.
Signed-off-by: NJay Fenlason <fenlason@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:

This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).

I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread).  So I
CC'ed this to KVM camp.  Comments are appreciated.

A pointer to dma_mapping_ops to struct dev_archdata is added.  If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it.  If it's
NULL, the system-wide dma_ops pointer is used as before.

If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging).  It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.

The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations.  So x86 can't have dma_mapping_ops per
device.  Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.

The first patch adds the device argument to dma_mapping_error.  The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.

This patch:

dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations.  So we can't have dma_mapping_ops per device.

Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function.  x86 IOMMUs use device
argument.

[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Isochronous reception in dualbuffer mode is reportedly broken with
TI TSB43AB22A on x86-64.  Descriptor addresses above 2G have been
determined as the trigger:
https://bugzilla.redhat.com/show_bug.cgi?id=435550

Two fixes are possible:
  - pci_set_consistent_dma_mask(pdev, DMA_31BIT_MASK);
    at least when IR descriptors are allocated, or
  - simply don't use dualbuffer.
This fix implements the latter workaround.

But we keep using dualbuffer on x86-32 which won't give us highmen (and
thus physical addresses outside the 31bit range) in coherent DMA memory
allocations.  Right now we could for example also whitelist PPC32, but
DMA mapping implementation details are expected to change there.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

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

The messages which can be enabled by fw-ohci's debug module parameter
are changed from KERN_DEBUG to KERN_NOTICE level and uniformly prefixed
with "firewire_ohci: ".  This further simplifies communication with
users when we ask them to capture debug messages.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

OHCI 1.1 clause 5.10 requires that selfIDBufferPtr is valid when a 1 is
written into LinkControl.rcvSelfID.

This driver bug has so far not been known to cause harm because most
chips obviously accept a later selfIDBufferPtr write, at least before
HCControl.linkEnable is written.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: NKristian Høgsberg <krh@redhat.com>

We want the rcvPhyPkt bit in LinkControl off before we start using the
chip.  However, the spec says that the reset value of it is undefined.
Hence switch it explicitly off.

https://bugzilla.redhat.com/show_bug.cgi?id=244576#c48 shows that for
example the nForce2 integrated FireWire controller seems to have it on
by default.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

header_length and payload_length are filled with random data if an
unknown tcode was read from the AR buffer (i.e. if the AR buffer
contained invalid data).

We still need a better strategy to recover from this, but at least
handle_ar_packet now doesn't return out of bound buffer addresses
anymore.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

request_generation is internal to fw-ohci and unneeded in fw_card.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Unlike the ohci1394 driver, fw-ohci uses the selfIDGeneration field of
bus reset packets to determine the generation of incoming requests as
per OHCI 1.1 clause 8.4.2.3.  This is more precise --- provided that the
controller inserts the correct generation.  Texas Instruments chips
often don't.

This prevented the transmission of response packets, which for example
broke AV/C transactions as used when communicating with miniDV cameras
and any other AV/C devices.

There is apparently no way to detect and adjust incorrect generations.
Therefore we ignore the generation of bus reset packets from TI chips
and use the generation of the self ID buffer instead.  Alas this is
received at a slightly wrong time.  In rare cases, this could cause us
to not respond to legitimate requests or to respond to expired requests.
(The latter is less likely because the bus reset packet AR event is
typically handled before the self ID complete event.)

Bug reported by Mladen Kuntner, who was extraordinarily patient while
dealing with the driver maintainers.  Fix confirmed to be required and
effective for TSB82AA2 and a TSB43AB22 or TSB43AB22A.
https://bugzilla.redhat.com/show_bug.cgi?id=243081Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

Extend the logging of "AR evt_bus_reset, link internal" to "AR
evt_bus_reset, generation ${selfIDGeneration}".  That way we can check
whether this generation matches the one seen in self ID complete event
logging.  See OHCI 1.1 clause 8.4.2.3.

Also extend logging of "firewire_ohci: * selfIDs, generation *" by
"local node ID ffc*" in self ID logging to make the local node in AT/AR
event logs more obvious.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

Add a debug option to watch bus reset interrupt events.  Half of this
patch is taken from Jarod Wilson's first version of the JMicron fix.

BusReset interrupts are only generated if the respective module
parameter flag was set before the controller is being initialized.
Else we keep this event masked to reduce IRQ load in normal operation
and to avoid potential problems with buggy chips.

Note, this is unlike the other IRQ events whose logging can be enabled
any time after chip initialization.  This and the influence on what
interrupts the chip generates is why I added an extra flag for it.

Also, reorder the debug parameter flags according to their perceived
usefulness.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJarod Wilson <jwilson@redhat.com>

I finally tracked down the issues with this JMicron PCI-e card in my
possession to a failure to comply with section 7.2.3.2 of the OHCI 1.1
specification (thanks to Kristian for the pointer to illustrate that it
is indeed a flaw in this card, not the driver). The controller should
simply flush the packets we've appended to its AT queue if a bus reset
occurs before they've been transmitted and we'll try again, but
something goes wrong and the controller winds up hung.

However, we can avoid the problem by simply checking if the
IntEvent.busReset register had been set before we try appending to the
AT context. When busReset is set, the AT context is completely halted
until busReset is cleared, so there's no point in appending AT packets
until the register is cleared. So at_context_queue_packet() now checks
for busReset being set, and bails with an RCODE_GENERATION packet ack,
which results in us trying to append the packet again after recognizing
the fact there has been a bus reset, and clearing busReset.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

While trying to debug this piece of crap JMicron PCI-e controller in my
possession, one thought was that perhaps I was encountering register access
failures. I'm not, but logging them would be good, so we can see if they
are a real problem we should be taking into account anywhere in the code.
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (added list contact)

I've now witnessed multiple occasions where one of my controllers (a very
poorly working JMicron PCIe card) fails to get its registers properly set
up in ohci_enable(), apparently due to an occasionally very slow to
initiate SClk. The easy fix for this problem is to add a tiny while loop
to try again a time or three after initially enabling LPS before we
move on (or give up).

Of course, the card still isn't fully functional yet, but this gets it at
least one tiny step closer...
Signed-off-by: NJarod Wilson <jwilson@redhat.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Balance ohci_pmac_on and ohci_pmac_off if pci_driver.probe fails.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>