There's an ugly little memory leak in firewire-ohci's
ar_context_tasklet(), where we're not freeing up some of the memory we
use for each ar_buffer, due to a moving pointer. The problem has been
there for a while, but didn't get noticed until after converting the AR
routines over to use coherent DMA and I started running into I/O stall-
outs with the following message output repeatedly to the console:
PCI-DMA: Out of IOMMU space for 53248 bytes at device 0000:04:09.0
Plugging this leak is definitely necessary, but unfortunately, isn't the
entire answer to my problem, it only increases the amount of I/O that I
can do before hitting the problem. Still working on tracking down the
root cause..
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This fixes a use-after-free bug in the handling of split transactions.
The AT DMA handler of the request was occasionally executed after the
AR DMA handler of the response. The AT DMA handler then accessed an
already freed packet.
Reported by Johannes Berg.
http://bugzilla.kernel.org/show_bug.cgi?id=9617
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Shut up "may be used uninitialised in this function" warnings due to
PPC32's implementation of dma_alloc_coherent().
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Currently, we do nothing to guarantee we have a consistent DMA buffer for
asynchronous receive packets. Rather than doing several sync's following a
dma_map_single() to get consistent buffers, just switch to using
dma_alloc_coherent().
Resolves constant buffer failures on my own x86_64 laptop w/4GB of RAM and
likely to fix a number of other failures witnessed on x86_64 systems with
4GB of RAM or more.
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Fix I/O errors due to SYM13FW500's inability to handle larger request
sizes. Reported by Piergiorgio Sartor <piergiorgio.sartor@nexgo.de> in
https://bugzilla.redhat.com/show_bug.cgi?id=436879
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Remove some less necessary information, point out that video1394 and
dv1394 should be blacklisted along with ohci1394.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Per the SBP-2 specification, all SBP-2 target devices must have a BUSY_TIMEOUT
register. Per the 1394-1995 specification, the retry_limt portion of the
register should be set to 0x0 initially, and set on the target by a logged in
initiator (i.e., a Linux host w/firewire controller(s)).
Well, as it turns out, lots of devices these days have actually moved on to
starting to implement SBP-3 compliance, which says that retry_limit should
default to 0xf instead (yes, SBP-3 stomps directly on 1394-1995, oops).
Prior to this change, the firewire driver stack didn't touch retry_limit, and
any SBP-3 compliant device worked fine, while SBP-2 compliant ones were unable
to retransmit when the host returned an ack_busy_X, which resulted in stalled
out I/O, eventually causing the SCSI layer to give up and offline the device.
The simple fix is for us to set retry_limit to 0xf in the register for all
devices (which actually matches what the old ieee1394 stack did).
Prior to this change, a hard disk behind an SBP-2 Prolific PL-3507 bridge chip
would routinely encounter buffer I/O errors and wind up offlined by the SCSI
layer. With this change, I've encountered zero I/O failures moving tens of GB
of data around.
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Mostly copied from ohci1394.c. Necessary for some older Macs, e.g.
PowerBook G3 Pismo and early PowerBook G4 Titanium.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Copied from ohci1394.c. This code is necessary to prevent machine check
exceptions when reloading or resuming the driver.
Tested on a 1st generation PowerBook G4 Titanium, which also needs the
pci_probe() hunk.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
I was able to reproduce the system exception on resume with a 3rd-gen
Titanium PowerBook G4 667, and this patch does let the system resume
successfully now.
Not quite clear if there was possibly an updated version coming using
pci_enable_device() instead of the pair of pmac_call_feature() calls,
but either way, this is a definite must-have, at least for older ppc
macs -- my Aluminum PowerBook G4/1.67 suspends and resumes without this
patch just fine.
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Kills warnings from 'make C=1 CHECKFLAGS="-D__CHECK_ENDIAN__" modules':
drivers/firewire/fw-transaction.c:771:10: warning: incorrect type in assignment (different base types)
drivers/firewire/fw-transaction.c:771:10: expected unsigned int [unsigned] [usertype] <noident>
drivers/firewire/fw-transaction.c:771:10: got restricted unsigned int [usertype] <noident>
drivers/firewire/fw-transaction.h:93:10: warning: incorrect type in assignment (different base types)
drivers/firewire/fw-transaction.h:93:10: expected unsigned int [unsigned] [usertype] <noident>
drivers/firewire/fw-transaction.h:93:10: got restricted unsigned int [usertype] <noident>
drivers/firewire/fw-ohci.c:1490:8: warning: restricted degrades to integer
drivers/firewire/fw-ohci.c:1490:35: warning: restricted degrades to integer
drivers/firewire/fw-ohci.c:1516:5: warning: cast to restricted type
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
The generation of incoming requests was filled in in wrong byte order on
machines with big endian CPU.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
The bus management workqueue job was in danger to dereference NULL
pointers. Also, after having temporarily lifted card->lock, a few node
pointers and a device pointer may have become invalid.
Add NULL pointer checks and get the necessary references. Also, move
card->local_node out of fw_card_bm_work's sight during shutdown of the
card.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Patch "firewire: fw-sbp2: fix NULL pointer deref. in scsi_remove_device"
had the unintended effect that firewire-sbp2 could not be unloaded
anymore until all SBP-2 devices were unplugged.
We now fix the NULL pointer bug by reacquiring a reference to the sdev
instead of holding a reference to the sdev (and to the module) all the
time.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Jarod Wilson <jwilson@redhat.com>
By supplying ioctl()s in the wrong order, a userspace client was able to
trigger NULL pointer dereferences. Furthermore, by calling
ioctl_create_iso_context more than once, new contexts could be created
without ever freeing the previously created contexts.
Thanks to Anders Blomdell for the report.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Fix a kernel bug when unplugging an SBP-2 device after having its
scsi_device already removed via the "delete" sysfs attribute.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
While fw-sbp2 takes the necessary time to reconnect to a logical unit
after bus reset, the SCSI core keeps sending new commands. They are all
immediately completed with host busy status, and application clients or
filesystems will break quickly. The SCSI device might even be taken
offline: http://bugzilla.kernel.org/show_bug.cgi?id=9734
The only remedy seems to be to block the SCSI device until reconnect.
Alas the SCSI core has no useful API to block only one logical unit i.e.
the scsi_device, therefore we block the entire Scsi_Host. This
currently corresponds to an SBP-2 target. In case of targets with
multiple logical units, we need to satisfy the dependencies between
logical units by carefully tracking the blocking state of the target and
its units. We block all logical units of a target as soon as one of
them needs to be blocked, and keep them blocked until all of them are
ready to be unblocked.
Furthermore, as the history of the old sbp2 driver has shown, the
scsi_block_requests() API is a minefield with high potential of
deadlocks. We therefore take extra measures to keep logical units
unblocked during __scsi_add_device() and during shutdown.
This avoids I/O errors during reconnect in many but alas not in all
cases. There may still be errors after a re-login had to be performed.
Also, some bridges have been seen to cease fetching management ORBs if
I/O went on up until a bus reset. In these cases, all management ORBs
time out after mgt_orb_timeout. The old sbp2 driver is less vulnerable
or maybe not vulnerable to this, for as yet unknown reasons.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
fw-sbp2 is unable to reconnect while performing __scsi_add_device
because there is only a single workqueue thread context available for
both at the moment. This should be fixed eventually.
An actual failure of __scsi_add_device is easy to handle, but an
incomplete execution of __scsi_add_device with an sdev returned would
remain undetected and leave the SBP-2 target unusable.
Therefore we use a workaround: If there was a bus reset during
__scsi_add_device (i.e. during the SCSI probe), we remove the new sdev
immediately, log out, and attempt login and SCSI probe again.
Tested-by: Jarod Wilson <jwilson@redhat.com> (earlier version)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
If fw-sbp2 was too late with requesting the reconnect, the target would
reject this. In this case, log out before attempting the reconnect.
Else several firmwares will deny the re-login because they somehow
didn't invalidate the old login.
Also, don't retry reconnects in this situation. The retries won't
succeed either.
These changes improve chances for successful re-login and shorten the
period during which the logical unit is inaccessible.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
When a reconnect failed but re-login succeeded, __scsi_add_device was
called again.
In those cases, __scsi_add_device succeeded and returned the pointer to
the existing scsi_device. fw-sbp2 then continued orderly, except that
it missed to call sbp2_cancel_orbs. SCSI core would call fw-sbp2's
eh_abort_handler eventually if there had been an outstanding command.
This patch avoids the needless lookups and temporary allocations in SCSI
core and I/O stall and timeout until eh_abort_handler hits.
Also, __scsi_add_device tolerating calls for devices which already exist
is undocumented behavior on which we shouldn't rely.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
for easier readable logs if more than one SBP-2 device is present.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Like the old sbp2 driver, wait for the write transaction to the
AGENT_RESET to complete before proceeding (after login, after reconnect,
or in SCSI error handling).
There is one occasion where AGENT_RESET is written to from atomic
context when getting DEAD status for a command ORB. There we still
continue without waiting for the transaction to complete because this
is more difficult to fix...
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Several different SBP-2 bridges accept a login early while the IDE
device is still powering up. They are therefore unable to respond to
SCSI INQUIRY immediately, and the SCSI core has to retry the INQUIRY.
One of these retries is typically successful, and all is well.
But in case of Momobay FX-3A, the INQUIRY retries tend to fail entirely.
This can usually be avoided by waiting a little while after login before
letting the SCSI core send the INQUIRY. The old sbp2 driver handles
this more gracefully for as yet unknown reasons (perhaps because it
waits for fetch agent resets to complete, unlike fw-sbp2 which quickly
proceeds after requesting the agent reset). Therefore the workaround is
not as much necessary for sbp2.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
This should help to interpret user reports. E.g. one can look up the
vendor OUI (first three bytes of the GUID) and thus tell what is what.
Also simplifies the math in the GUID sysfs attribute.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
If a device is being unplugged while fw-sbp2 had a login or reconnect on
schedule, it would take about half a minute to shut the fw_unit down:
Jan 27 18:34:54 stein firewire_sbp2: logged in to fw2.0 LUN 0000 (0 retries)
<unplug>
Jan 27 18:34:59 stein firewire_sbp2: sbp2_scsi_abort
Jan 27 18:34:59 stein scsi 25:0:0:0: Device offlined - not ready after error recovery
Jan 27 18:35:01 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:06 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:12 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:17 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:22 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:27 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:32 stein firewire_sbp2: orb reply timed out, rcode=0x11
Jan 27 18:35:32 stein firewire_sbp2: failed to login to fw2.0 LUN 0000
Jan 27 18:35:32 stein firewire_sbp2: released fw2.0
After this patch, typically only a few seconds spent in __scsi_add_device
remain:
Jan 27 19:05:50 stein firewire_sbp2: logged in to fw2.0 LUN 0000 (0 retries)
<unplug>
Jan 27 19:05:56 stein firewire_sbp2: sbp2_scsi_abort
Jan 27 19:05:56 stein scsi 33:0:0:0: Device offlined - not ready after error recovery
Jan 27 19:05:56 stein firewire_sbp2: released fw2.0
The benefit of this is less noise in the syslog. It furthermore avoids
a few wasted CPU cycles and needlessly prolonged lifetime of a few
driver objects.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
There is a race between shutdown and creation of devices: fw-core may
attempt to add a device with the same name of an already existing
device. http://bugzilla.kernel.org/show_bug.cgi?id=9828
Impact of the bug: Happens rarely (when shutdown of a device coincides
with creation of another), forces the user to unplug and replug the new
device to get it working.
The fix is obvious: Free the minor number *after* instead of *before*
device_unregister(). This requires to take an additional reference of
the fw_device as long as the IDR tree points to it.
And while we are at it, we fix an additional race condition:
fw_device_op_open() took its reference of the fw_device a little bit too
late, hence was in danger to access an already invalid fw_device.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This fixes a "can't recognize device" kind of bug.
If the SCSI INQUIRY failed and hence __scsi_add_device failed due to a
bus reset, we tried a logout and then waited for the already scheduled
login work to happen. So far so good, but the generation used for the
logout was outdated, hence the logout never reached the target. The
target might therefore deny the subsequent relogin attempt, which would
also leave the target inaccessible.
Therefore fetch a fresh device->generation for the logout. Use memory
barriers to prevent our plan being foiled by compiler or hardware
optimizations.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
To be more compliant with section 7.4.8 of the SBP-2 specification,
use the mgt_ORB_timeout specified in the SBP-2 device's config rom
for login ORB attempts (though with some sanity checks). A happy
side-effect is that certain device and controller combinations that
sometimes take more than 20 seconds to get synced up (like my laptop
with just about any SBP-2 device) now function more reliably.
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (silenced sparse)
Increase (and rename) the login orb reply timeout value to 20s
to match that of the old firewire stack. 2s simply didn't give
many devices enough time to spin up and reply.
Fixes inability to recognize some devices.
Failure mode was "orb reply timed out"/"failed to login".
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (style, comments, changelog)
Replace an unnecessary subtraction with a bitwise AND when determining the
value of ext_tcode in fw_fill_transaction() to save a cpu cycle or two in a
somewhat critical path.
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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: Stefan 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: Jarod 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=429950
Signed-off-by: Stefan 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: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Kristian 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: Stefan 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: Jarod 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: Stefan 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: Jarod 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: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Jarod 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: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Jarod 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: David Moore <dcm@acm.org>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Jarod 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: Stefan 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 57fdb58fa5. 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: Stefan Richter <stefanr@s5r6.in-berlin.de>
Fix extraction of the source node id from the packet header.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Stefan 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: David Moore <dcm@acm.org>
Signed-off-by: Stefan 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: David Moore <dcm@acm.org>
Signed-off-by: Stefan 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: Stefan 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James 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: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
