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: Stefan Richter <stefanr@s5r6.in-berlin.de>
reread_bus_info_block() only gets to see devices whose config_rom_length
is at least 6 (ROM header, bus info block, root directory header).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The kernel API documentation says that queue_delayed_work() returns 0
(only) if the work was already queued. The return codes of
schedule_delayed_work() are not documented but the same.
In init_iso_resource(), the work has never been queued yet, hence we
can assume schedule_delayed_work() to be a guaranteed success there.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Some fixes:
- Remove stale documentation.
- Fix a != vs. == thinko that got in the way of channel management.
- Try bandwidth deallocation even if channel deallocation failed.
A simplification:
- fw_cdev_allocate_iso_resource.channels is now ordered like
libdc1394's dc1394_iso_allocate_channel() channels_allowed
argument.
By the way, I looked closer at cards from NEC, TI, and VIA, and noticed
that they all don't implement IEEE 1394a behaviour which is meant to
deviate from IEEE 1212's notion of lock compare-swap. This means that
we have to do two lock transactions instead of one in many cases where
one transaction would already succeed on a fully 1394a compliant IRM.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
DMA must be halted before we DMA-unmap and free the DMA buffer. Since
we cannot rely on the client to stop the context before it closes the
fd, we have to reorder fw_iso_buffer_destroy vs. fw_iso_context_destroy.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
All of these functions are entered with IRQs enabled.
Hence the unconditional spin_unlock_irq can be used.
Function: Caller context:
dequeue_event() client process, via read(2)
fill_bus_reset_event() fw-device.c update worqueue job
release_client_resource() client process, via ioctl(2)
fw_device_op_release() client process, via close(2)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Make the size check of ioctl_send_request and
ioctl_send_broadcast_request speed dependent. Also change the error
return code from -EINVAL to -EIO to distinguish this from other errors
concerning the ioctl parameters.
Another payload size limit for which we don't check here though is the
remote node's Bus_Info_Block.max_rec.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
We don't want random users write to Memory Space (e.g. PCs with physical
DMA filters down) or to core CSRs like Reset_Start.
This does not protect SBP-2 target CSRs. But properly behaving SBP-2
targets ignore broadcast write requests to these registers, and the
maximum damage which can happen with laxer targets is DOS. But there
are ways to create DOS situations anyway if there are devices with weak
device file permissions (like audio/video devices) present at the same
bus as an SBP-2 target.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Write transactions to the broadcast node ID are a convenient way to
trigger functions of multiple nodes at once. IIDC is a protocol which
can make use of this if multiple cameras with same command_regs_base are
connected at the same bus.
Based on
Date: Wed, 10 Sep 2008 11:32:16 -0400
From: Jay Fenlason <fenlason@redhat.com>
Subject: [patch] SEND_BROADCAST_REQUEST
Changes: ioctl_send_request() and ioctl_send_broadcast_request() now
share code. Broadcast speed corrected to S100. Check for proper tcode.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
While the speed of asynchronous transactions is automatically chosen by
the kernel, the speed of isochronous streams has to be chosen by the
initiating client.
In case of 1394a bus topologies, the maximum possible speed could be
figured out with some effort by evaluation of the remote node's link
speed field in the config ROM, the local node's link speed field, and
the PHY speeds and topologic information in the local node's or IRM's
topology map CSR. However, this does not work in case of 1394b buses.
Hence add an ioctl to export the maximum speed which the kernel already
determined.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This adds ioctls for allocation and deallocation of a channel or/and
bandwidth without auto-reallocation and without auto-deallocation.
The benefit of these ioctls is that libraw1394-style isochronous
resource management can be implemented without write access to the IRM's
character device file.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Based on
Date: Tue, 18 Nov 2008 11:41:27 -0500
From: Jay Fenlason <fenlason@redhat.com>
Subject: [Patch V4] Add ISO resource management support
with several changes to the ABI and implementation. Only the part of
the ABI which enables auto-reallocation and auto-deallocation is
included here.
This implements ioctls for kernel-assisted allocation of isochronous
channels and isochronous bandwidth. The benefits are:
- The client does not have to have write access to the /dev/fw* device
corresponding to the IRM.
- The client does not have to perform reallocation after bus resets.
- Channel and bandwidth are deallocated by the kernel if the file is
closed before the client deallocated the resources. Thus resources
are released even if the client crashes.
It is anticipated that future in-kernel code (firewire-core IRM code;
the firewire port of firedtv), will use the fw-iso.c portions of this
code too.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: David Moore <dcm@acm.org>
to indicate that they are specializations of struct event or of struct
client_resource, respectively.
struct response was both an event and a client_resource; it is now split
into struct outbound_transaction_resource and ~_event in order to
document more explicitly which types of client resources exist.
struct request and struct_request_event are renamed to struct
inbound_transaction_resource and ~_event because requests and responses
occur in outbound and in inbound transactions.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The lifetime of struct client instances must be longer than the lifetime
of any client resource.
This fixes a possible race between fw_device_op_release and transaction
completions. It also prepares for new ioctls for isochronous resource
management which will involve delayed processing of client resources.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reviewed-by: David Moore <dcm@acm.org>
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>
Like before my commit 1415d9189e,
fw_core_add_address_handler() does not align the address region now.
Instead the caller is required to pass valid parameters.
Since one of the callers of fw_core_add_address_handler() is the cdev
userspace interface, we now check for valid input. If the client is
buggy, we give it a hint with -EINVAL.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The current code uses a linked list and a counter for storing
resources and the corresponding handle numbers. By changing to an idr
we can be safe from counter wrap-around giving two resources the same
handle.
Furthermore, the deallocation ioctls now check whether the resource to
be freed is of the intended type.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Some rework by Stefan R:
- The idr API documentation says we get an ID within 0...0x7fffffff.
Hence we can rest assured that idr handles fit into cdev handles.
- Fix some races. Add a client->in_shutdown flag for this purpose.
- Add allocation retry to add_client_resource().
- It is possible to use idr_for_each() in fw_device_op_release().
- Fix ioctl_send_response() regression.
- Small style changes.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Unlink the client from the fw_device earlier in order to prevent bus
reset events being added to client->event_list during shutdown.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The behaviour of fw-transaction.c::fw_send_request is ill-defined for
any other tcodes than read/ write/ lock request tcodes. Therefore
prevent requests with wrong tcodes from entering the transaction layer.
Maybe fw_send_request should check them itself, but I am not inclined to
change it and fw_fill_request from void-valued functions to ones which
return error codes and pass those up. Besides, maybe fw_send_request is
going to support one more tcode than ioctl_send_request in the future
(TCODE_STREAM_DATA).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This adds a client_list_lock, which only protects the device's
client_list, so that future versions of the driver can call code that
takes the card->lock while holding the client_list_lock. Adding this
lock is much simpler than adding __ versions of all the functions that
the future version may need. The one ordering issue is to make sure
code never takes the client_list_lock with card->lock held. Since
client_list_lock is only used in three places, that isn't hard.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Update fill_bus_reset_event() accordingly. Include linux/spinlock.h.
Signed-off-by: Stefan 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: David Moore <dcm@acm.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
After a controller initialization failure, addition of another card got
stuck due to card_list corruption.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
According to https://bugs.launchpad.net/bugs/294391
- 3rd generation iPods need the "fix capacity" workaround after all
(apparently they crash after the last sector was accessed),
- 2nd generation iPods need the "128 kB maximum request size"
workaround.
Alas both iPod generations feature the same model ID in the config ROM,
hence we can only define a shared quirks list entry for them. Luckily
the fix capacity workaround did not show a negative effect in Jarod's
tests with 2nd gen. iPod.
A side note: Apple computers in target mode (or at least an x86 Mac
mini) don't have firmware_version and model_id, hence none of the iPod
quirks list entries is active for them.
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reported-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
who also provided a first version of the fix.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
1394-2008 clause 16.3.4.1 (1394b-2002 clause 16.3.1.1) defines tighter
limits than 1394-2008 clause 6.2.2.3 (1394a-2000 clause 6.2.2.3).
Our previously too large limit doesn't matter though if the controller
reports its max_receive correctly.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This fixes a regression by "firewire: keep highlevel drivers attached
during brief connection loss": There were 2 seconds unnecessary waiting
added to the shutdown procedure of each controller.
We use card->link as status flag to signal the device handler that there
is no use to wait for a come-back.
Signed-off-by: Stefan 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: Stefan 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: Stefan Richter <stefanr@s5r6.in-berlin.de>
There are situations when nodes vanish from the bus and come back
quickly thereafter:
- When certain bus-powered hubs are plugged in,
- when certain devices are plugged into 6-port hubs,
- when certain disk enclosures are switched from self-power to bus
power or vice versa and break the daisy chain during the transition,
- when the user plugs a cable out and quickly plugs it back in, e.g.
to reorder a daisy chain (works on Mac OS X if done quickly enough),
- when certain hubs temporarily malfunction during high bus traffic.
Until now, firewire-core reported affected nodes as lost to the
highlevel drivers (firewire-sbp2 and userspace drivers). We now delay
the destruction of device representations until after at least two
seconds after the last bus reset. If a "new" device is detected in this
period whose bus information block and root directory header match that
of a device which is pending for deletion, we resurrect that device and
send update calls to highlevel drivers.
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>
The whole topology code only works if the old and new topologies which
are compared come from immediately successive self ID complete events.
If there happened bus resets without self ID complete events in the
meantime, or self ID complete events with invalid selfIDs, the topology
comparison could identify nodes wrongly, or more likely just corrupt
kernel memory or panic right away.
We now discard all nodes of the old topology and treat all current nodes
as new ones if the current self ID generation is not the previous one
plus 1.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Due to commit 2831fe6f9c, "driver core:
create a private portion of struct device", device_initialize() can no
longer be called from atomic contexts.
We now defer it until after config ROM probing. This requires changes
to the bus manager code because this may use a device before it was
probed.
Reported-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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)
