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>
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>
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>
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: Kristian Hoegsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
New warning since commit ab88ca488b,
"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: Stefan 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: Stefan Richter <stefanr@s5r6.in-berlin.de>
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: Stefan Richter <stefanr@s5r6.in-berlin.de>
at_context_queue_packet() didn't clean up in an early exit path.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
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: Stefan Richter <stefanr@s5r6.in-berlin.de>
Fixes (papers over) "Sleep problems with kernels >= 2.6.21 on powerpc",
http://lkml.org/lkml/2007/8/25/155. The issue is that the FireWire
controller's pci_dev.current_state of iBook G3 and presumably older
PowerBooks is still in PCI_UNKNOWN instead of PCI_D0 when the firewire
driver's .suspend method is called.
Like it was suggested earlier in http://lkml.org/lkml/2006/10/24/13, we
do not fail .suspend anymore if pci_set_power_state failed.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
descriptor.data_address is little endian
Tested-by: Olaf Hering <olh@suse.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
It's a low-impact design, that just makes suspend/resume look like
a bus reset to the upper level drivers, but it should be sufficient.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
need it for page_private(), not all targets have it pulled indirectly
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch loads fw-sbp2 if sbp2 is still in the config file. So one can
go back and forth between releases without worry about the root
filesystem drivers.
Signed-off-by: Kristian Hoegsberg <krh@redhat.com>
Existing mkinitrd scripts still have to be adapted, unless they grok
module aliases.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Drop filenames from file preamble, drop editor annotations and
use standard indent style for block comments.
Signed-off-by: Kristian Hoegsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (fixed typo)
Setting these at create_context time or start_iso time doesn't matter
much, but raw1394 sets them at start_iso time so that will be easier to
emulate this way.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The dualbuffer DMA setup did not account for the iso trailer word
and thus didn't work correctly. With this fixed we can drop the
dual buffer fallback mode.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The old async transmit context handling was starting and stopping
DMA for every packet transmission. This could cause silently failing
packet transmission, if the DMA was reprogrammed too close to being
stopped.
The general context code keeps DMA running at all times and fixes this
problem. It's also a nice cleanup.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Some flaky controllers doesn't honor the masterIntEnable bits
and can generate bus reset events even if that bit is cleared.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The obsolete SA_xxx interrupt flags have been used despite the scheduled
removal. Fixup the remaining users in -mm.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
We need the channel number as we queue up iso packets for transmission
so we can fill out the header correctly.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
When a DMA descriptor is appended to the context we sync it for
DMA and the device might potentially read it immediately. So,
we can't set the IRQ bits in the descriptor after appending.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
When the DMA is setup to not strip any headers, we need to use
the buffer fill descriptor instead of the dual buffer, since the
dual buffer descriptor must strip a non-zero number of header quadlets.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
