ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/motu/Makefile b/sound/firewire/motu/Makefile
index ae84ae61d27404ced5af21998142f28880489513..728f586e754b64437ba05db96e70e0c0b66a6292 100644 (file)
--- 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 (file)
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 08bd1760b1b40771f74bb37fb9740df673b67c09..2c77e8bb5424c9d22a7c9f1852de2a31085c7f40 100644 (file)
--- 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;
 }