The current implementation of Bus_Time read access was buggy since it
did not ensure that Bus_Time.second_count_hi and second_count_lo came
from the same 128 seconds period.
Reported-by: Håkan Johansson <f96hajo@chalmers.se>
Instead of a fix, remove Bus_Time register support altogether. The spec
requires all cycle master capable nodes to implement this (all Linux
nodes are cycle master capable) while it also says that it "may" be
initialized by the bus manager or by the IRM standing in for a bus
manager. (Neither Linux' firewire-core nor ieee1394 nodemgr implement
this.)
Since we cannot rely on Bus_Time having been initialized by a bus
manager, it is better to return an error instead of a nonsensical value
on a read request to Bus_Time.
Alternatively, we could fix the Bus_Time read integrity bug _and_
implement (a) cycle master's write support of the register as well as
(b) bus manager's Bus_Time initialization service, i.e. preservation of
the Bus_Time when the cycle master node of a bus changes. However, that
would be quite some code for a feature that is unreliable to begin with
and very likely unused in practice.
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)
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>
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>
This register is 1 kBytes large. Adjust topology_map.length to prevent
registration of other response handlers in this region and to make sure
that we respond to requests to the upper half of the register.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tlabel is a 6 bits wide datum. Wrap it after 63 rather than 31 for more
safety against transaction label exhaustion and potential responders'
transaction layer bugs. (As noted by Guus Sliepen, this change requires
an expansion of tlabel_mask to 64 bits.)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The source files of firewire-core, firewire-ohci, firewire-sbp2, i.e.
"drivers/firewire/fw-*.c"
are renamed to
"drivers/firewire/core-*.c",
"drivers/firewire/ohci.c",
"drivers/firewire/sbp2.c".
The old fw- prefix was redundant to the directory name. The new core-
prefix distinguishes the files according to which driver they belong to.
This change comes a little late, but still before further firewire
drivers are added as anticipated RSN.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Stefan Richter