[PATCH 0/3] ALSA: firewire-lib/firewire-motu: add tracepoints for IEC 61883-1/6 variants

[PATCH 0/3] ALSA: firewire-lib/firewire-motu: add tracepoints for IEC 61883-1/6 variants

[Takashi Sakamoto]

Hi,

ALSA IEC 61883-1/6 engine already supports some tracepoints to probe events
for a part of parameters about incoming/outgoing packets. The main purpose
of the tracepoints to assists users/developers for further work to the
engine. For example, users can gather the parameters and developers use it
to investigate quirks of actual units. Actually, as I reported [0], some
drivers in ALSA firewire stack seems to have timestamping issue which have
never resolved by any Free Software [1], and further investigation is
required for users/developers to improves the engine.

My recent works add support for some variants of IEC 61883-1/6. Existent
tracepoints are unavailable for a part of the variants. Furthermore,
in a part of the variants, presentation timestamp is transferred by
a different way against IEC 61883-1/6. It's better to trace packet
parameters for the variants, as well as for compliant protocols to
IEC 61883-1/6.

This patchset adds some tracepoints for the purpose, mainly for RME
Fireface series and MOTU FireWire series. Below code/command is a sample to
work with perf(1) for tracepoints on ALSA driver for MOTU FireWire series,
added at third patch. The final command outputs contents of data chunks for
message from units. Please install or build perf command with python 2
support, in advance.

$ cat ./motu.py
import os
import sys

sys.path.append(os.environ['PERF_EXEC_PATH'] + \
    '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')

from perf_trace_context import *
from Core import *

# For a case that several MOTU FireWire units on the same bus.
cycles = {}

def snd_firewire_lib__in_packet(name, context, cpu, secs, nsecs,
                                pid, comm, callchain,
                                second, cycle, channel, src, dest,
                                cip_header0, cip_header1, payload_quadlets,
                                packet_index, irq, index):
    global cycles

    if src not in cycles:
        cycles[src] = {}
    cycles[src]['sec'] = second
    cycles[src]['cycle'] = cycle

def snd_firewire_motu__in_data_block_message(name, context, cpu, secs, nsecs,
                                             pid, comm, callchain,
                                             src, dst, data_blocks, messages):
    global cycles

    if src not in cycles:
        return

    print('{0} sec {1} cycle'.format(cycles[src]['sec'], cycles[src]['cycle']))
    for i in range(data_blocks):
        offset = i * 8
        msg = messages[offset:offset + 8]
        print('    {0}: {1[5]:02x}{1[4]:02x}{1[3]:02x}{1[2]:02x}{1[1]:02x}{1[0]:02x}'.format(i, msg))
$ ~/linux.git/tools/perf/perf record -a -e snd_firewire_motu:in_data_block_message -e snd_firewire_lib:in_packet
^C
$ PERF_EXEC_PATH=~/linux.git/tools/perf/ ~/linux.git/tools/perf/perf script -s ./motu.py
...
7 sec 7999 cycle
    0: 000000805854
    1: 0000008050fc
    2: 0000808050a4
    3: 00003f80504c
    4: 0000008048f4
    5: 00000080489c
    6: 000080804844
    7: 00003f8040ec
0 sec 0 cycle
0 sec 1 cycle
    0: 000000804094
    1: 0000008050fc
    2: 0000808050a4
    3: 00003f80504c
    4: 0000008048f4
    5: 00000080489c
    6: 000080804844
    7: 00003f8058ac
0 sec 2 cycle
    0: 000000805854
    1: 0000008050fc
    2: 0000808050a4
    3: 00003f80504c
    4: 0000008048f4
    5: 00000080605c
    6: 000080806004
    7: 00003f8058ac
...

[0] [alsa-devel] Dice packet sequence quirk and ALSA firewire stack in Linux 4.6
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-May/107715.html
[1] This is not resolved in FFADO, user space library to drive the units, too.
Some workarounds are applied to the library, but it can not work well depending
on units and protocols.

Takashi Sakamoto (3):
  ALSA: firewire_lib: add tracepoints for packets without CIP headers
  ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion
  ALSA: firewire-motu: add tracepoints for messages for unique protocol

 sound/firewire/amdtp-stream-trace.h    |  88 +++++++++++++++++++++++
 sound/firewire/amdtp-stream.c          |   8 +++
 sound/firewire/motu/Makefile           |   2 +
 sound/firewire/motu/amdtp-motu-trace.h | 123 +++++++++++++++++++++++++++++++++
 sound/firewire/motu/amdtp-motu.c       |  37 ++++++++++
 5 files changed, 258 insertions(+)
 create mode 100644 sound/firewire/motu/amdtp-motu-trace.h

-- 
2.9.3

[PATCH 1/3] ALSA: firewire_lib: add tracepoints for packets without CIP headers

[Takashi Sakamoto]

Unique protocol is used for RME Fireface series. In this protocol,
payload format for isochronous packet is not compliant to CIP in
IEC 61883-1/6. The packet includes data blocks just with data channels,
without headers and any metadata.

In previous commits, ALSA IEC 61883-1/6 engine supports this protocol.
However, tracepoints are not supported yet, unlike implementation for
IEC 61883-1/6 protocol. This commit adds support of tracepoints for
the protocol.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 sound/firewire/amdtp-stream-trace.h | 88 +++++++++++++++++++++++++++++++++++++
 sound/firewire/amdtp-stream.c       |  8 ++++
 2 files changed, 96 insertions(+)

diff --git a/sound/firewire/amdtp-stream-trace.h b/sound/firewire/amdtp-stream-trace.h
index 850b36e..ea0d486 100644
--- a/sound/firewire/amdtp-stream-trace.h
+++ b/sound/firewire/amdtp-stream-trace.h
@@ -101,6 +101,94 @@ TRACE_EVENT(out_packet,
 		__entry->index)
 );
 
+TRACE_EVENT(in_packet_without_header,
+	TP_PROTO(const struct amdtp_stream *s, u32 cycles, unsigned int payload_quadlets, unsigned int data_blocks, unsigned int index),
+	TP_ARGS(s, cycles, payload_quadlets, data_blocks, index),
+	TP_STRUCT__entry(
+		__field(unsigned int, second)
+		__field(unsigned int, cycle)
+		__field(int, channel)
+		__field(int, src)
+		__field(int, dest)
+		__field(unsigned int, payload_quadlets)
+		__field(unsigned int, data_blocks)
+		__field(unsigned int, data_block_counter)
+		__field(unsigned int, packet_index)
+		__field(unsigned int, irq)
+		__field(unsigned int, index)
+	),
+	TP_fast_assign(
+		__entry->second = cycles / CYCLES_PER_SECOND;
+		__entry->cycle = cycles % CYCLES_PER_SECOND;
+		__entry->channel = s->context->channel;
+		__entry->src = fw_parent_device(s->unit)->node_id;
+		__entry->dest = fw_parent_device(s->unit)->card->node_id;
+		__entry->payload_quadlets = payload_quadlets;
+		__entry->data_blocks = data_blocks,
+		__entry->data_block_counter = s->data_block_counter,
+		__entry->packet_index = s->packet_index;
+		__entry->irq = !!in_interrupt();
+		__entry->index = index;
+	),
+	TP_printk(
+		"%02u %04u %04x %04x %02d %03u %3u %3u %02u %01u %02u",
+		__entry->second,
+		__entry->cycle,
+		__entry->src,
+		__entry->dest,
+		__entry->channel,
+		__entry->payload_quadlets,
+		__entry->data_blocks,
+		__entry->data_block_counter,
+		__entry->packet_index,
+		__entry->irq,
+		__entry->index)
+);
+
+TRACE_EVENT(out_packet_without_header,
+	TP_PROTO(const struct amdtp_stream *s, u32 cycles, unsigned int payload_length, unsigned int data_blocks, unsigned int index),
+	TP_ARGS(s, cycles, payload_length, data_blocks, index),
+	TP_STRUCT__entry(
+		__field(unsigned int, second)
+		__field(unsigned int, cycle)
+		__field(int, channel)
+		__field(int, src)
+		__field(int, dest)
+		__field(unsigned int, payload_quadlets)
+		__field(unsigned int, data_blocks)
+		__field(unsigned int, data_block_counter)
+		__field(unsigned int, packet_index)
+		__field(unsigned int, irq)
+		__field(unsigned int, index)
+	),
+	TP_fast_assign(
+		__entry->second = cycles / CYCLES_PER_SECOND;
+		__entry->cycle = cycles % CYCLES_PER_SECOND;
+		__entry->channel = s->context->channel;
+		__entry->src = fw_parent_device(s->unit)->card->node_id;
+		__entry->dest = fw_parent_device(s->unit)->node_id;
+		__entry->payload_quadlets = payload_length / 4;
+		__entry->data_blocks = data_blocks,
+		__entry->data_blocks = s->data_block_counter,
+		__entry->packet_index = s->packet_index;
+		__entry->irq = !!in_interrupt();
+		__entry->index = index;
+	),
+	TP_printk(
+		"%02u %04u %04x %04x %02d %03u %02u %03u %02u %01u %02u",
+		__entry->second,
+		__entry->cycle,
+		__entry->src,
+		__entry->dest,
+		__entry->channel,
+		__entry->payload_quadlets,
+		__entry->data_blocks,
+		__entry->data_block_counter,
+		__entry->packet_index,
+		__entry->irq,
+		__entry->index)
+);
+
 #endif
 
 #undef TRACE_INCLUDE_PATH
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index a03b37b..f6af8e6 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -479,6 +479,10 @@ static int handle_out_packet_without_header(struct amdtp_stream *s,
 	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
 
 	payload_length = data_blocks * 4 * s->data_block_quadlets;
+
+	trace_out_packet_without_header(s, cycle, payload_length, data_blocks,
+					index);
+
 	if (queue_out_packet(s, payload_length) < 0)
 		return -EIO;
 
@@ -617,6 +621,10 @@ static int handle_in_packet_without_header(struct amdtp_stream *s,
 
 	buffer = s->buffer.packets[s->packet_index].buffer;
 	data_blocks = payload_quadlets / s->data_block_quadlets;
+
+	trace_in_packet_without_header(s, cycle, payload_quadlets, data_blocks,
+				       index);
+
 	pcm_frames = s->process_data_blocks(s, buffer, data_blocks, NULL);
 	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
 
-- 
2.9.3

[PATCH 2/3] ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion

[Takashi Sakamoto]

Unique protocol is used for MOTU FireWire series. In this protocol,
data block format is not compliant to AM824 in IEC 61883-1/6. Each of
the data block consists of 24 bit data chunks, except for a first
quadlet. The quadlet is used for source packet header (SPH) described
in IEC 61883-1.

The sequence of SPH seems to represent presentation timestamp
corresponding to included data. Developers have experienced that invalid
sequence brings disorder of units in the series.

Unfortunately, current implementation of ALSA IEC 61883-1/6 engine and
firewire-motu driver brings periodical noises to the units at sampling
transmission frequency based on 44.1 kHz. The engine generates the SPH with
even interval and this mechanism seems not to be suitable to the units.
Further work is required for this issue and infrastructure is preferable
to assist the work.

This commit adds tracepoints for the purpose. In the tracepoints, events
are probed to gather the SPHs from each data blocks.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 sound/firewire/motu/Makefile           |  2 +
 sound/firewire/motu/amdtp-motu-trace.h | 73 ++++++++++++++++++++++++++++++++++
 sound/firewire/motu/amdtp-motu.c       | 20 ++++++++++
 3 files changed, 95 insertions(+)
 create mode 100644 sound/firewire/motu/amdtp-motu-trace.h

diff --git a/sound/firewire/motu/Makefile b/sound/firewire/motu/Makefile
index ae84ae6..728f586 100644
--- a/sound/firewire/motu/Makefile
+++ b/sound/firewire/motu/Makefile
@@ -1,3 +1,5 @@
+CFLAGS_amdtp-motu.o	:= -I$(src)
+
 snd-firewire-motu-objs := motu.o amdtp-motu.o motu-transaction.o motu-stream.o \
 			  motu-proc.o motu-pcm.o motu-midi.o motu-hwdep.o \
 			  motu-protocol-v2.o motu-protocol-v3.o
diff --git a/sound/firewire/motu/amdtp-motu-trace.h b/sound/firewire/motu/amdtp-motu-trace.h
new file mode 100644
index 0000000..5862bf9
--- /dev/null
+++ b/sound/firewire/motu/amdtp-motu-trace.h
@@ -0,0 +1,73 @@
+/*
+ * amdtp-motu-trace.h - tracepoint definitions to dump a part of packet data
+ *
+ * Copyright (c) 2017 Takashi Sakamoto
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM		snd_firewire_motu
+
+#if !defined(_SND_FIREWIRE_MOTU_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _SND_FIREWIRE_MOTU_TRACE_H
+
+#include <linux/tracepoint.h>
+
+static void copy_sph(u32 *frame, __be32 *buffer, unsigned int data_blocks,
+		     unsigned int data_block_quadlets);
+
+TRACE_EVENT(in_data_block_sph,
+	TP_PROTO(struct amdtp_stream *s, unsigned int data_blocks, __be32 *buffer),
+	TP_ARGS(s, data_blocks, buffer),
+	TP_STRUCT__entry(
+		__field(int, src)
+		__field(int, dst)
+		__field(unsigned int, data_blocks)
+		__dynamic_array(u32, tstamps, data_blocks)
+	),
+	TP_fast_assign(
+		__entry->src = fw_parent_device(s->unit)->node_id;
+		__entry->dst = fw_parent_device(s->unit)->card->node_id;
+		__entry->data_blocks = data_blocks;
+		copy_sph(__get_dynamic_array(tstamps), buffer, data_blocks, s->data_block_quadlets);
+	),
+	TP_printk(
+		"%04x %04x %u %s",
+		__entry->src,
+		__entry->dst,
+		__entry->data_blocks,
+		__print_array(__get_dynamic_array(tstamps), __entry->data_blocks, 4)
+	)
+);
+
+TRACE_EVENT(out_data_block_sph,
+	TP_PROTO(struct amdtp_stream *s, unsigned int data_blocks, __be32 *buffer),
+	TP_ARGS(s, data_blocks, buffer),
+	TP_STRUCT__entry(
+		__field(int, src)
+		__field(int, dst)
+		__field(unsigned int, data_blocks)
+		__dynamic_array(u32, tstamps, data_blocks)
+	),
+	TP_fast_assign(
+		__entry->src = fw_parent_device(s->unit)->card->node_id;
+		__entry->dst = fw_parent_device(s->unit)->node_id;
+		__entry->data_blocks = data_blocks;
+		copy_sph(__get_dynamic_array(tstamps), buffer, data_blocks, s->data_block_quadlets);
+	),
+	TP_printk(
+		"%04x %04x %u %s",
+		__entry->src,
+		__entry->dst,
+		__entry->data_blocks,
+		__print_array(__get_dynamic_array(tstamps), __entry->data_blocks, 4)
+	)
+);
+
+#endif
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH	.
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE	amdtp-motu-trace
+#include <trace/define_trace.h>
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c
index 08bd176..2c77e8b 100644
--- a/sound/firewire/motu/amdtp-motu.c
+++ b/sound/firewire/motu/amdtp-motu.c
@@ -10,6 +10,9 @@
 #include <sound/pcm.h>
 #include "motu.h"
 
+#define CREATE_TRACE_POINTS
+#include "amdtp-motu-trace.h"
+
 #define CIP_FMT_MOTU		0x02
 #define CIP_FMT_MOTU_TX_V3	0x22
 #define MOTU_FDF_AM824		0x22
@@ -264,6 +267,19 @@ static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 	}
 }
 
+/* For tracepoints. */
+static void copy_sph(u32 *frames, __be32 *buffer, unsigned int data_blocks,
+		     unsigned int data_block_quadlets)
+{
+	unsigned int i;
+
+	for (i = 0; i < data_blocks; ++i) {
+		*frames = be32_to_cpu(*buffer);
+		buffer += data_block_quadlets;
+		frames++;
+	}
+}
+
 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 				__be32 *buffer, unsigned int data_blocks,
 				unsigned int *syt)
@@ -271,6 +287,8 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 	struct amdtp_motu *p = s->protocol;
 	struct snd_pcm_substream *pcm;
 
+	trace_in_data_block_sph(s, data_blocks, buffer);
+
 	if (p->midi_ports)
 		read_midi_messages(s, buffer, data_blocks);
 
@@ -346,6 +364,8 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
 
 	write_sph(s, buffer, data_blocks);
 
+	trace_out_data_block_sph(s, data_blocks, buffer);
+
 	return data_blocks;
 }
 
-- 
2.9.3

[PATCH 3/3] ALSA: firewire-motu: add tracepoints for messages for unique protocol

[Takashi Sakamoto]

MOTU units transfer/receive messages in each data block of their
isochronous packet payload. A part of content in the message is cleard for
MIDI message transmission, while the rest is unknown yet. Additional
features are required to assist users and developers to reveal the
details.

This commit adds tracepoints for the purpose. The tracepoints are designed
for MOTU's protocol version 2 and 3 (Protocol version 1 is not upstreamed
yet). In the tracepoints, events are probed to gather first two 24 bit
data chunks of each data block. The chunks are formatted into elements
of 64 bit array with padding in MSB.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 sound/firewire/motu/amdtp-motu-trace.h | 50 ++++++++++++++++++++++++++++++++++
 sound/firewire/motu/amdtp-motu.c       | 17 ++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/sound/firewire/motu/amdtp-motu-trace.h b/sound/firewire/motu/amdtp-motu-trace.h
index 5862bf9..cd0cbfa9 100644
--- a/sound/firewire/motu/amdtp-motu-trace.h
+++ b/sound/firewire/motu/amdtp-motu-trace.h
@@ -15,6 +15,8 @@
 
 static void copy_sph(u32 *frame, __be32 *buffer, unsigned int data_blocks,
 		     unsigned int data_block_quadlets);
+static void copy_message(u64 *frames, __be32 *buffer, unsigned int data_blocks,
+			 unsigned int data_block_quadlets);
 
 TRACE_EVENT(in_data_block_sph,
 	TP_PROTO(struct amdtp_stream *s, unsigned int data_blocks, __be32 *buffer),
@@ -64,6 +66,54 @@ TRACE_EVENT(out_data_block_sph,
 	)
 );
 
+TRACE_EVENT(in_data_block_message,
+	TP_PROTO(struct amdtp_stream *s, unsigned int data_blocks, __be32 *buffer),
+	TP_ARGS(s, data_blocks, buffer),
+	TP_STRUCT__entry(
+		__field(int, src)
+		__field(int, dst)
+		__field(unsigned int, data_blocks)
+		__dynamic_array(u64, messages, data_blocks)
+	),
+	TP_fast_assign(
+		__entry->src = fw_parent_device(s->unit)->node_id;
+		__entry->dst = fw_parent_device(s->unit)->card->node_id;
+		__entry->data_blocks = data_blocks;
+		copy_message(__get_dynamic_array(messages), buffer, data_blocks, s->data_block_quadlets);
+	),
+	TP_printk(
+		"%04x %04x %u %s",
+		__entry->src,
+		__entry->dst,
+		__entry->data_blocks,
+		__print_array(__get_dynamic_array(messages), __entry->data_blocks, 8)
+	)
+);
+
+TRACE_EVENT(out_data_block_message,
+	TP_PROTO(struct amdtp_stream *s, unsigned int data_blocks, __be32 *buffer),
+	TP_ARGS(s, data_blocks, buffer),
+	TP_STRUCT__entry(
+		__field(int, src)
+		__field(int, dst)
+		__field(unsigned int, data_blocks)
+		__dynamic_array(u64, messages, data_blocks)
+	),
+	TP_fast_assign(
+		__entry->src = fw_parent_device(s->unit)->card->node_id;
+		__entry->dst = fw_parent_device(s->unit)->node_id;
+		__entry->data_blocks = data_blocks;
+		copy_message(__get_dynamic_array(messages), buffer, data_blocks, s->data_block_quadlets);
+	),
+	TP_printk(
+		"%04x %04x %u %s",
+		__entry->src,
+		__entry->dst,
+		__entry->data_blocks,
+		__print_array(__get_dynamic_array(messages), __entry->data_blocks, 8)
+	)
+);
+
 #endif
 
 #undef TRACE_INCLUDE_PATH
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c
index 2c77e8b..996b5f8 100644
--- a/sound/firewire/motu/amdtp-motu.c
+++ b/sound/firewire/motu/amdtp-motu.c
@@ -280,6 +280,21 @@ static void copy_sph(u32 *frames, __be32 *buffer, unsigned int data_blocks,
 	}
 }
 
+/* For tracepoints. */
+static void copy_message(u64 *frames, __be32 *buffer, unsigned int data_blocks,
+			 unsigned int data_block_quadlets)
+{
+	unsigned int i;
+
+	/* This is just for v2/v3 protocol. */
+	for (i = 0; i < data_blocks; ++i) {
+		*frames = (be32_to_cpu(buffer[1]) << 16) |
+			  (be32_to_cpu(buffer[2]) >> 16);
+		buffer += data_block_quadlets;
+		frames++;
+	}
+}
+
 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 				__be32 *buffer, unsigned int data_blocks,
 				unsigned int *syt)
@@ -288,6 +303,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 	struct snd_pcm_substream *pcm;
 
 	trace_in_data_block_sph(s, data_blocks, buffer);
+	trace_in_data_block_message(s, data_blocks, buffer);
 
 	if (p->midi_ports)
 		read_midi_messages(s, buffer, data_blocks);
@@ -365,6 +381,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
 	write_sph(s, buffer, data_blocks);
 
 	trace_out_data_block_sph(s, data_blocks, buffer);
+	trace_out_data_block_message(s, data_blocks, buffer);
 
 	return data_blocks;
 }
-- 
2.9.3

Re: [PATCH 0/3] ALSA: firewire-lib/firewire-motu: add tracepoints for IEC 61883-1/6 variants

[Takashi Iwai]

On Sun, 09 Apr 2017 14:33:26 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> ALSA IEC 61883-1/6 engine already supports some tracepoints to probe events
> for a part of parameters about incoming/outgoing packets. The main purpose
> of the tracepoints to assists users/developers for further work to the
> engine. For example, users can gather the parameters and developers use it
> to investigate quirks of actual units. Actually, as I reported [0], some
> drivers in ALSA firewire stack seems to have timestamping issue which have
> never resolved by any Free Software [1], and further investigation is
> required for users/developers to improves the engine.
> 
> My recent works add support for some variants of IEC 61883-1/6. Existent
> tracepoints are unavailable for a part of the variants. Furthermore,
> in a part of the variants, presentation timestamp is transferred by
> a different way against IEC 61883-1/6. It's better to trace packet
> parameters for the variants, as well as for compliant protocols to
> IEC 61883-1/6.
> 
> This patchset adds some tracepoints for the purpose, mainly for RME
> Fireface series and MOTU FireWire series. Below code/command is a sample to
> work with perf(1) for tracepoints on ALSA driver for MOTU FireWire series,
> added at third patch. The final command outputs contents of data chunks for
> message from units. Please install or build perf command with python 2
> support, in advance.
> 
> $ cat ./motu.py
> import os
> import sys
> 
> sys.path.append(os.environ['PERF_EXEC_PATH'] + \
>     '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
> 
> from perf_trace_context import *
> from Core import *
> 
> # For a case that several MOTU FireWire units on the same bus.
> cycles = {}
> 
> def snd_firewire_lib__in_packet(name, context, cpu, secs, nsecs,
>                                 pid, comm, callchain,
>                                 second, cycle, channel, src, dest,
>                                 cip_header0, cip_header1, payload_quadlets,
>                                 packet_index, irq, index):
>     global cycles
> 
>     if src not in cycles:
>         cycles[src] = {}
>     cycles[src]['sec'] = second
>     cycles[src]['cycle'] = cycle
> 
> def snd_firewire_motu__in_data_block_message(name, context, cpu, secs, nsecs,
>                                              pid, comm, callchain,
>                                              src, dst, data_blocks, messages):
>     global cycles
> 
>     if src not in cycles:
>         return
> 
>     print('{0} sec {1} cycle'.format(cycles[src]['sec'], cycles[src]['cycle']))
>     for i in range(data_blocks):
>         offset = i * 8
>         msg = messages[offset:offset + 8]
>         print('    {0}: {1[5]:02x}{1[4]:02x}{1[3]:02x}{1[2]:02x}{1[1]:02x}{1[0]:02x}'.format(i, msg))
> $ ~/linux.git/tools/perf/perf record -a -e snd_firewire_motu:in_data_block_message -e snd_firewire_lib:in_packet
> ^C
> $ PERF_EXEC_PATH=~/linux.git/tools/perf/ ~/linux.git/tools/perf/perf script -s ./motu.py
> ...
> 7 sec 7999 cycle
>     0: 000000805854
>     1: 0000008050fc
>     2: 0000808050a4
>     3: 00003f80504c
>     4: 0000008048f4
>     5: 00000080489c
>     6: 000080804844
>     7: 00003f8040ec
> 0 sec 0 cycle
> 0 sec 1 cycle
>     0: 000000804094
>     1: 0000008050fc
>     2: 0000808050a4
>     3: 00003f80504c
>     4: 0000008048f4
>     5: 00000080489c
>     6: 000080804844
>     7: 00003f8058ac
> 0 sec 2 cycle
>     0: 000000805854
>     1: 0000008050fc
>     2: 0000808050a4
>     3: 00003f80504c
>     4: 0000008048f4
>     5: 00000080605c
>     6: 000080806004
>     7: 00003f8058ac
> ...
> 
> [0] [alsa-devel] Dice packet sequence quirk and ALSA firewire stack in Linux 4.6
> http://mailman.alsa-project.org/pipermail/alsa-devel/2016-May/107715.html
> [1] This is not resolved in FFADO, user space library to drive the units, too.
> Some workarounds are applied to the library, but it can not work well depending
> on units and protocols.
> 
> Takashi Sakamoto (3):
>   ALSA: firewire_lib: add tracepoints for packets without CIP headers
>   ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion
>   ALSA: firewire-motu: add tracepoints for messages for unique protocol

Applied all three patches now.  Thanks.


Takashi