Instead of starting the split transaction timeout timer when any request
is submitted, start it only when the destination's ACK_PENDING has been
received. This prevents us from using a timeout that is too short, and,
if the controller's AT queue is emptying very slowly, from cancelling
a packet that has not yet been sent.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Change the header of PHY packets to be sent to include a pseudo
transaction code. This makes the header consistent with that of
received PHY packets, and allows at_context_queue_packet() and
log_ar_at_event() to see the packet type directly instead of having
to deduce it from the header length or even from the header contents.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Because we might be in interrupt context, replace del_timer_sync() with
del_timer(). If the timer is already running, we know that it will
clean up the transaction, so we do not need to do any further processing
in the normal transaction handler.
Many thanks to Yong Zhang for diagnosing this.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
region->end is defined as an upper bound of the requested address range,
exclusive --- i.e. as an address outside of the range in which the
requested CSR is to be placed.
Hence 0x0001,0000,0000,0000 is the biggest valid region->end, not
0x0000,ffff,ffff,fffc like the current check asserted.
For simplicity, the fix drops the region->end & 3 test because there is
no actual problem with these bits set in region->end. The allocated
address range will be quadlet aligned and of a size of multiple quadlets
due to the checks for region->start & 3 and handler->length & 3 alone.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add an FW_CDEV_IOC_RECEIVE_PHY_PACKETS ioctl() and
FW_CDEV_EVENT_PHY_PACKET_RECEIVED poll()/read() event for /dev/fw*.
This can be used to get information from remote PHYs by remote access
PHY packets.
This is also the 2nd half of the functionality (the receive part) to
support a userspace implementation of a VersaPHY transaction layer.
Safety considerations:
- PHY packets are generally broadcasts, hence some kind of elevated
privileges should be required of a process to be able to listen in
on PHY packets. This implementation assumes that a process that is
allowed to open the /dev/fw* of a local node does have this
privilege.
There was an inconclusive discussion about introducing POSIX
capabilities as a means to check for user privileges for these
kinds of operations.
Other limitations:
- PHY packet reception may be switched on by ioctl() but cannot be
switched off again. It would be trivial to provide an off switch,
but this is not worth the code. The client should simply close()
the fd then, or just ignore further events.
- For sake of simplicity of API and kernel-side implementation, no
filter per packet content is provided.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
core-transaction.c transmit_complete_callback() and close_transaction()
expect packet callback status to be an ACK or RCODE, and ACKs get
translated to RCODEs for transaction callbacks.
An old comment on the packet callback API (been there from the initial
submission of the stack) and the dummy_driver implementation of
send_request/send_response deviated from this as they also included
-ERRNO in the range of status values.
Let's narrow status values down to ACK and RCODE to prevent surprises.
RCODE_CANCELLED is chosen as the dummy_driver's RCODE as its meaning of
"transaction timed out" comes closest to what happens when a transaction
coincides with card removal.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Bus resets which are triggered
- by the kernel drivers after updates of the local nodes' config ROM,
- by userspace software via ioctl
shall be deferred until after >=2 seconds after the last bus reset.
If multiple modifications of the local nodes' config ROM happen in a row,
only a single bus reset should happen after them.
When the local node's link goes from inactive to active or vice versa,
and at the two occasions of bus resets mentioned above --- and if the
current gap count differs from 63 --- the bus reset should be preceded
by a PHY configuration packet that reaffirms the gap count. Otherwise a
bus manager would have to reset the bus again right after that.
This is necessary to promote bus stability, e.g. leave grace periods for
allocations and reallocations of isochronous channels and bandwidth,
SBP-2 reconnections etc.; see IEEE 1394 clause 8.2.1.
This change implements all of the above by moving bus reset initiation
into a delayed work (except for bus resets which are triggered by the
bus manager workqueue job and are performed there immediately). It
comes with a necessary addition to the card driver methods that allows
to get the current gap count from PHY registers.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The present inline documentation of the fw_send_request() in-kernel API
refers to userland code that is not applicable to kernel drivers at all.
Reported-by: Ben Gamari <bgamari.foss@gmail.com>
While we are at fixing the whole documentation of fw_send_request(),
also improve the rest of firewire-core's kerneldoc comments:
- Add a bit of text concerning fw_run_transaction()'s call parameters.
- Append () to function names and tab-align parameter descriptions as
suggested by the example in Documentation/kernel-doc-nano-HOWTO.txt.
- Remove kerneldoc markers from comments on static functions.
- Remove outdated parameter descriptions at build_tree().
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
When a remote device does a LOCK_REQUEST, the core does not pass
the extended tcode to userspace. This patch makes it use the
juju-specific tcodes listed in firewire-constants.h for incoming
requests.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
This matches how tcode in the API for outbound requests is treated.
Affects kernelspace and userspace drivers alike, but at the moment there
are no kernespace drivers that receive lock requests.
Split out from a combo patch, slightly reordered, changelog reworded.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
void (*fw_address_callback_t)(..., int speed, ...) is the speed that a
remote node chose to transmit a request to us. In case of split
transactions, firewire-core will transmit the response at that speed.
Upper layer drivers on the other hand (firewire-net, -sbp2, firedtv, and
userspace drivers) cannot do anything useful with that speed datum,
except log it for debug purposes. But data that is merely potentially
(not even actually) used for debug purposes does not belong into the API.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
which caused gcc 4.6 to warn about
variable 'destination' set but not used.
Since the hardware ensures that we receive only response packets with
proper destination node ID (in a given bus generation), we have no use
for destination here in the core as well as in upper layers.
(This is different with request packets. There we pass destination node
ID to upper layers because they may for example need to check whether
this was an unicast or broadcast request.)
Reported-and-Tested-By: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Rather than "read a Control and Status Registers (CSR) Architecture
register" I prefer to say "read a Control and Status Register".
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
All of these CSRs have the same read/ write/ aynthing-else handling,
except for CSR_PRIORITY_BUDGET which might not be implemented.
The CSR_CYCLE_TIME read handler implementation accepted 4-byte-sized
block write requests before this change but this is just silly; the
register is only required to support quadlet read and write requests
like the other r/w CSR core and Serial-Bus-dependent registers.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Push the maintenance of STATE_CLEAR/SET.abdicate down into the card
driver. This way, the read/write_csr_reg driver method works uniformly
across all CSR offsets.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
by feature variables in the fw_card struct. The hook appeared to be an
unnecessary abstraction in the card driver interface.
Cleaner would be to pass those feature flags as arguments to
fw_card_initialize() or fw_card_add(), but the FairnessControl register
is in the SCLK domain and may therefore not be accessible while Link
Power Status is off, i.e. before the card->driver->enable call from
fw_card_add().
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add a comment on which of the conflicting NODE_IDS specifications we
implement. Reduce a comment on rather irrelevant register bits that can
all be looked up in the spec (or from now on in the code history).
Directly include the required indirectly included bug.h.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Implement the abdicate bit, which is required for bus manager
capable nodes and tested by the Base 1394 Test Suite.
Finally, something to do at a command reset! :-)
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the cmstr bit, which is required for cycle master capable
nodes and tested for by the Base 1394 Test Suite.
This bit allows the bus master to disable cycle start packets; there are
bus master implementations that actually do this.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the MAIN_UTILITY register, which is utterly optional
but useful as a safe target for diagnostic read/write/broadcast
transactions.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
If supported by the OHCI controller, implement the PRIORITY_BUDGET
register, which is required for nodes that can use asynchronous
priority arbitration.
To allow the core to determine what features the lowlevel device
supports, add a new card driver callback.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the BUS_TIME register, which is required for cycle master
capable nodes and tested for by the Base 1393 Test Suite. Even when
there is not yet bus master initialization support, this register allows
us to work together with other bus masters.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
The specification requires that CYCLE_TIME is writable so that it can be
initialized, so we better implement it.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the SPLIT_TIMEOUT registers. Besides being required by the
spec, this is desirable for some IIDC devices and necessary for many
audio devices to be able to increase the timeout from userspace.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Clemens Ladisch
Joe Perches
Stefan Richter
Jay Fenlason