The block layer calling convention is blk_queue_<limit name>.
blk_queue_max_sectors predates this practice, leading to some confusion.
Rename the function to appropriately reflect that its intended use is to
set max_hw_sectors.
Also introduce a temporary wrapper for backwards compability. This can
be removed after the merge window is closed.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In isochronous transmit DMA descriptors, link the skip address pointer
back to the descriptor itself. When a cycle is lost, the controller
will send the packet in the next cycle, instead of terminating the
entire DMA program.
There are two reasons for this:
* This behaviour is compatible with the old IEEE1394 stack. Old
applications would not expect the DMA program to stop in this case.
* Since the OHCI driver does not report any uncompleted packets, the
context would stop silently; clients would not have any chance to
detect and handle this error without a watchdog timer.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Pieter Palmers notes:
"The reason I added this retry behavior to the old stack is because some
cards now and then fail to send a packet (e.g. the o2micro card in my
dell laptop). I couldn't figure out why exactly this happens, my best
guess is that the card cannot fetch the payload data on time. This
happens much more frequently when sending large packets, which leads me
to suspect that there are some contention issues with the DMA that fills
the transmit FIFO.
In the old stack it was a pretty critical issue as it resulted in a
freeze of the userspace application.
The omission of a packet doesn't necessarily have to be an issue. E.g.
in IEC61883 streams the DBC field can be used to detect discontinuities
in the stream. So as long as the other side doesn't bail when no
[packet] is present in a cycle, there is not really a problem.
I'm not convinced though that retrying is the proper solution, but it is
simple and effective for what it had to do. And I think there are no
reasons not to do it this way. Userspace can still detect this by
checking the cycle the descriptor was sent in."
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog, comment)
In the transmit path of firewire-net (IPv4 over 1394), the following
race condition may occur:
- The networking soft IRQ inserts a datagram into the 1394 async
request transmit DMA.
- The 1394 async transmit completion tasklet runs to finish cleaning
up (unlink datagram from list of pending ones, release skb and
outbound 1394 transaction object) --- before the networking soft IRQ
had a chance to proceed and add the datagram to the list of pending
datagrams.
This caused a panic in the 1394 async transmit completion tasklet when
it dereferenced unitialized list heads:
http://bugzilla.kernel.org/show_bug.cgi?id=15077
The fix is to add checks in the tx soft IRQ and in the tasklet to
determine which of these two is the last referrer to the transaction
object. Then handle the cleanup of the object by the last referrer
rather than assuming that the tasklet is always the last one.
There is another similar race: Between said tasklet and fwnet_close,
i.e. at ifdown. However, that race is much less likely to occur in
practice and shall be fixed in a separate update.
Reported-by: Илья Басин <basinilya@gmail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Unsurprisingly, Texas Instruments TSB43AB23 exhibits the same behaviour
as TSB43AB22/A in dual buffer IR DMA mode: If descriptors are located
at physical addresses above the 31 bit address range (2 GB), the
controller will overwrite random memory. With luck, this merely
prevents video reception. With only a little less luck, the machine
crashes.
We use the same workaround here as with TSB43AB22/A: Switch off the
dual buffer capability flag and use packet-per-buffer IR DMA instead.
Another possible workaround would be to limit the coherent DMA mask to
31 bits.
In Linux 2.6.33, this change serves effectively only as documentation
since dual buffer mode is not used for any controller anymore. But
somebody might want to re-enable it in the future to make use of
features of dual buffer DMA that are not available in packet-per-buffer
mode.
In Linux 2.6.32 and older, this update is vital for anyone with this
controller, more than 2 GB RAM, a 64 bit kernel, and FireWire video or
audio applications.
We have at least four reports:
http://bugzilla.kernel.org/show_bug.cgi?id=13808http://marc.info/?l=linux1394-user&m=126154279004083https://bugzilla.redhat.com/show_bug.cgi?id=552142http://marc.info/?l=linux1394-user&m=126432246128386
Reported-by: Paul Johnson
Reported-by: Ronneil Camara
Reported-by: G Zornetzer
Reported-by: Mark Thompson
Cc: stable@kernel.org
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Commit db5d247a "firewire: fix use of multiple AV/C devices, allow
multiple FCP listeners" introduced a regression into 2.6.33-rc3:
The core freed payloads of incoming requests to FCP_Request or
FCP_Response before a userspace driver accessed them.
We need to copy such payloads for each registered userspace client
and free the copies according to the lifetime rules of non-FCP client
request resources.
(This could possibly be optimized by reference counts instead of
copies.)
The presently only kernelspace driver which listens for FCP requests,
firedtv, was not affected because it already copies FCP frames into an
own buffer before returning to firewire-core's FCP handler dispatcher.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Presently, firewire-core only checks whether descriptors that are to be
added by userspace drivers to the local node's config ROM do not exceed
a size of 256 quadlets. However, the sum of the bare minimum ROM plus
all descriptors (from firewire-core, from firewire-net, from userspace)
must not exceed 256 quadlets.
Otherwise, the bounds of a statically allocated buffer will be
overwritten. If the kernel survives that, firewire-core will
subsequently be unable to parse the local node's config ROM.
(Note, userspace drivers can add descriptors only through device files
of local nodes. These are usually only accessible by root, unlike
device files of remote nodes which may be accessible to lesser
privileged users.)
Therefore add a test which takes the actual present and required ROM
size into account for all descriptors of kernelspace and userspace
drivers.
Cc: stable@kernel.org
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Update the Kconfig help texts of both stacks to encourage a general move
from the older to the newer drivers. However, do not label ieee1394 as
"Obsolete" yet, as the newer drivers have not been deployed as default
stack in the majority of Linux distributions yet, and those who start
doing so now may still want to install the old drivers as fallback for
unforeseen issues.
Since Linux 2.6.32, FireWire audio devices can be driven by the newer
firewire driver stack too, hence remove an outdated comment about audio
devices. Also remove comments about library versions since the 2nd
generation of libraw1394 and libdc1394 is now in common use; details on
library versions can be read at the wiki link from the help texts.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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: Stefan Richter <stefanr@s5r6.in-berlin.de>
If copy_from_user in an FW_CDEV_IOC_SEND_RESPONSE ioctl failed, the
fw_request pointed to by the inbound_transaction_resource is no
longer referenced and needs to be freed.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Control of more than one AV/C device at once --- e.g. camcorders, tape
decks, audio devices, TV tuners --- failed or worked only unreliably,
depending on driver implementation. This affected kernelspace and
userspace drivers alike and was caused by firewire-core's inability to
accept multiple registrations of FCP listeners.
The fix allows multiple address handlers to be registered for the FCP
command and response registers. When a request for these registers is
received, all handlers are invoked, and the Firewire response is
generated by the core and not by any handler.
The cdev API does not change, i.e., userspace is still expected to send
a response for FCP requests; this response is silently ignored.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog, rebased, whitespace)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: ohci: handle receive packets with a data length of zero
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: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: stable@kernel.org
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: ohci: pass correct iso xmit timestamps to core
firewire: ohci: Make cycleMatch ISO transmission work
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: Jay 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: Stefan 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: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (edited comment)
Replace a hardcoded buffer size by a sizeof union {}. This shrinks the
stack-allocated ioctl argument buffer from 256 to 40 bytes. (This is
not much, but subsequent stack usage particularly by the queue_iso ioctl
handler adds up.)
The new form is also easier to keep up to date than a hardcoded size if
more ioctls are added.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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: Stefan Richter <stefanr@s5r6.in-berlin.de>
In the code path which creates request packets, clearly mark a switch
branch which must never be reached with a WARN.
In the code path which creates response packets, replace a BUG by a
friendlier to debug WARN.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: sbp2: provide fallback if mgt_ORB_timeout is missing
ieee1394: add documentation entry to MAINTAINERS
ieee1394: update URLs in debugging-via-ohci1394.txt
The Topology Map of the local node was created in CPU byte order,
then a temporary big endian copy was created to compute the CRC,
and when a read request to the Topology Map arrived it had to be
converted to big endian byte order again.
We now generate it in big endian byte order in the first place.
This also rids us of 1000 bytes stack usage in tasklet context.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Move the static config ROM buffer into the scope of the two callers of
generate_config_rom(). That way the ROM length can be passed over as
return value rather than through a pointer argument.
It also becomes more obvious that accesses to the config ROM buffer have
to be serialized and how this is accomplished. And firewire-core.ko
shrinks a bit as well.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
