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: Stefan Richter <stefanr@s5r6.in-berlin.de>
Noticed by Jarod Wilson: The bus manager work was unnecessarily delayed
each time the bus generation counter rolled over.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
topology_map is by far the largest member in struct fw_card. Move it to
the very end of the struct so that card pointer dereferences have better
chances to hit the CPU cache.
This requires to increase the topology_map backing store to the size
specified in IEEE 1394, i.e. 256 rather than 255 quadlets. Otherwise
the topology_map response handler may access invalid memory.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
An earlier change, maybe long ago, removed the copying of self_id_count
into card->self_id_count. Since then each bus reset cleared
card->bm_retries even when it shouldn't.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Take a reference to the card whenever fw_card_bm_work() is scheduled on
that card and release it when the work is done. This allows us to
remove the cancel_delayed_work_sync() in fw_core_remove_card().
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (patch update)
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: Stefan Richter <stefanr@s5r6.in-berlin.de>
The "color" is used during the topology building after a bus reset,
hovever in "struct fw_node"s it is stored in a u8, but in struct fw_card
it is stored in an int. When the value wraps in one struct, but not
the other, disaster strikes.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=10922.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Share code between fw_send_request + wait_for_completion callers.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Addendum:
Removes an unnecessary struct and an ununsed retry loop.
Calls it fw_run_transaction() instead of fw_send_request_sync().
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Kristian Høgsberg <krh@redhat.com>
This is a functionally equivalent replacement of the current reference
counting of struct fw_card instances. It only converts it to common
idioms as suggested by Kristian Høgsberg:
- struct kref replaces atomic_t as the counter.
- wait_for_completion is used to wait for all card users to complete.
BTW, it may make sense to count card->flush_timer and card->work as
card users too.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The card->kref became obsolete since patch "firewire: fix crash in
automatic module unloading" added another counter of card users.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
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>
As far as I know, all CardBus FireWire 400 adapters have a maximum
payload of 1024 bytes which is less than the speed-dependent limit of
2048 bytes. Fw-sbp2 has to take the host adapter's limit into account.
This apparently fixes Juju's incompatibility with my CardBus cards, a
NEC based card and a VIA based card.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Kristian Høgsberg <krh@redhat.com>
Found and debugged by Jay Fenlason <fenlason@redhat.com>.
The bug was especially noticeable with direct I/O over fw-sbp2.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Table-based gap count optimization cannot be used if 1394b repeater PHYs
are present. But it does work with 1394b leaf nodes.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
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)
Signed-off-by: Marc Butler <marc@adaptivecode.com>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (added whitespace)
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 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>
This lets us break out "Juju" as the model name in the config rom.
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 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>
This patch splits out the iso buffer so we can initialize it at mmap
time with the size provided in the mmap call. Furthermore, allocate
the backing pages using alloc_page to avoid setting up kernel side
virtual memory mappings for the pages.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Drivers such as fw-sbp2 had no way to properly cancel in-progress
transactions, which could leave a pending transaction or an unset
packet in the low-level queues after kfree'ing the containing
structure. fw_cancel_transaction() lets drivers cancel a submitted
transaction.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Drop the negative errnos and use RCODEs for all error codes
in the complete transaction callback.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This patch contains the following cleanups:
- "extern inline" -> "static inline"
- fw-topology.c: make struct fw_node_create static
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Instances of struct file_operations and struct fw_card_driver can be
qualified as "const". Ditto with struct fw_descriptor.data, struct
fw_device_id, and predefined instances of struct fw_address_region,
at least in the current implementation.
Data qualified as const is placed into the .rodata section which won't
be mixed with dirty data.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
