Hi,
The purpose of this patchset is to remove a feature of firewire-lib module. I call it as 'full duplex streaming with timestamp synchronization'.
This patchset should accumulated into my previous RFC patchset below: [alsa-devel] [RFC][PATCH 0/3 v2] firewire-lib: support Linux tracing framework to dump a part of packet data http://mailman.alsa-project.org/pipermail/alsa-devel/2016-April/106950.html
The feature is based on a specification of IEC 61883-6. In the specification, an audio function block should reuse some parameters of incoming packets for outgoing packets. Current ALSA firewire stack partly implement it. However, actual audio and music units on IEEE 1394 bus don't expect drivers to perform the specification.
Additionally to the fact, the feature brings inconveniences to handle payloads of isochronous packet in software interrupts.
For these reasons, this patchset removes the feature from ALSA firewire stack. This decision may be a help for future improvement about dynamic interrupt interval of isochronous context, about which Clemens have mentioned[1].
[1][alsa-devel] For firewire drivers, reduce period time down to 2msec? http://mailman.alsa-project.org/pipermail/alsa-devel/2014-April/075696.html
Regards
Takashi Sakamoto (6): ALSA: bebob: drop reusing incoming packet parameter for outgoing packet parameter ALSA: fireworks: drop reusing incoming packet parameter for ougoing packet parameter ALSA: firewire-tascam: drop reusing incoming packet parameter for outgoing packet parameter ALSA: firewire-lib: handle IT/IR contexts in each software context ALSA: firewire-lib: code cleanup for incoming packet handling ALSA: firewire-lib: code cleanup for outgoing packet handling
sound/firewire/amdtp-stream.c | 84 ++++++++---------------- sound/firewire/amdtp-stream.h | 35 ++-------- sound/firewire/bebob/bebob.h | 1 - sound/firewire/bebob/bebob_stream.c | 99 ++++++++--------------------- sound/firewire/fireworks/fireworks.h | 1 - sound/firewire/fireworks/fireworks_stream.c | 84 +++++------------------- sound/firewire/tascam/tascam-stream.c | 26 ++++---- 7 files changed, 87 insertions(+), 243 deletions(-)