ALSA: pcm: tracepoints for refining PCM parameters

When working for devices which support configurable modes for its data
transmission or which consists of several components, developers are
likely to use rules of parameters of PCM substream. However, there's no
infrastructure to assist their work.

In old days, ALSA PCM core got a local 'RULES_DEBUG' macro to debug
refinement of parameters for PCM substream. Although this is merely a
makeshift. With some modifications, we get the infrastructure.

This commit is for the purpose. Refinement of mask/interval type of
PCM parameters is probed as tracepoint events as 'hw_mask_param' and
'hw_interval_param' on existent 'snd_pcm' subsystem.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 142 insertions, 0 deletions

diff --git a/sound/core/pcm_param_trace.h b/sound/core/pcm_param_trace.h
new file mode 100644
index 000000000000..872922326b38
--- /dev/null
+++ b/sound/core/pcm_param_trace.h
@@ -0,0 +1,142 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM snd_pcm
+
+#if !defined(_PCM_PARAMS_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _PCM_PARAMS_TRACE_H
+
+#include <linux/tracepoint.h>
+
+#define HW_PARAM_ENTRY(param) {SNDRV_PCM_HW_PARAM_##param, #param}
+#define hw_param_labels			\
+	HW_PARAM_ENTRY(ACCESS),		\
+	HW_PARAM_ENTRY(FORMAT),		\
+	HW_PARAM_ENTRY(SUBFORMAT),	\
+	HW_PARAM_ENTRY(SAMPLE_BITS),	\
+	HW_PARAM_ENTRY(FRAME_BITS),	\
+	HW_PARAM_ENTRY(CHANNELS),	\
+	HW_PARAM_ENTRY(RATE),		\
+	HW_PARAM_ENTRY(PERIOD_TIME),	\
+	HW_PARAM_ENTRY(PERIOD_SIZE),	\
+	HW_PARAM_ENTRY(PERIOD_BYTES),	\
+	HW_PARAM_ENTRY(PERIODS),	\
+	HW_PARAM_ENTRY(BUFFER_TIME),	\
+	HW_PARAM_ENTRY(BUFFER_SIZE),	\
+	HW_PARAM_ENTRY(BUFFER_BYTES),	\
+	HW_PARAM_ENTRY(TICK_TIME)
+
+TRACE_EVENT(hw_mask_param,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_hw_param_t type, int index, const struct snd_mask *prev, const struct snd_mask *curr),
+	TP_ARGS(substream, type, index, prev, curr),
+	TP_STRUCT__entry(
+		__field(int, card)
+		__field(int, device)
+		__field(int, subdevice)
+		__field(int, direction)
+		__field(snd_pcm_hw_param_t, type)
+		__field(int, index)
+		__field(int, total)
+		__array(__u32, prev_bits, 8)
+		__array(__u32, curr_bits, 8)
+	),
+	TP_fast_assign(
+		__entry->card = substream->pcm->card->number;
+		__entry->device = substream->pcm->device;
+		__entry->subdevice = substream->number;
+		__entry->direction = substream->stream;
+		__entry->type = type;
+		__entry->index = index;
+		__entry->total = substream->runtime->hw_constraints.rules_num;
+		memcpy(__entry->prev_bits, prev->bits, sizeof(__u32) * 8);
+		memcpy(__entry->curr_bits, curr->bits, sizeof(__u32) * 8);
+	),
+	TP_printk("%d,%d,%d,%d %03d/%03d %s %08x%08x%08x%08x %08x%08x%08x%08x",
+		  __entry->card,
+		  __entry->device,
+		  __entry->subdevice,
+		  __entry->direction,
+		  __entry->index,
+		  __entry->total,
+		  __print_symbolic(__entry->type, hw_param_labels),
+		  __entry->prev_bits[3], __entry->prev_bits[2],
+		  __entry->prev_bits[1], __entry->prev_bits[0],
+		  __entry->curr_bits[3], __entry->curr_bits[2],
+		  __entry->curr_bits[1], __entry->curr_bits[0]
+	)
+);
+
+TRACE_EVENT(hw_interval_param,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_hw_param_t type, int index, const struct snd_interval *prev, const struct snd_interval *curr),
+	TP_ARGS(substream, type, index, prev, curr),
+	TP_STRUCT__entry(
+		__field(int, card)
+		__field(int, device)
+		__field(int, subdevice)
+		__field(int, direction)
+		__field(snd_pcm_hw_param_t, type)
+		__field(int, index)
+		__field(int, total)
+		__field(unsigned int, prev_min)
+		__field(unsigned int, prev_max)
+		__field(unsigned int, prev_openmin)
+		__field(unsigned int, prev_openmax)
+		__field(unsigned int, prev_integer)
+		__field(unsigned int, prev_empty)
+		__field(unsigned int, curr_min)
+		__field(unsigned int, curr_max)
+		__field(unsigned int, curr_openmin)
+		__field(unsigned int, curr_openmax)
+		__field(unsigned int, curr_integer)
+		__field(unsigned int, curr_empty)
+	),
+	TP_fast_assign(
+		__entry->card = substream->pcm->card->number;
+		__entry->device = substream->pcm->device;
+		__entry->subdevice = substream->number;
+		__entry->direction = substream->stream;
+		__entry->type = type;
+		__entry->index = index;
+		__entry->total = substream->runtime->hw_constraints.rules_num;
+		__entry->prev_min = prev->min;
+		__entry->prev_max = prev->max;
+		__entry->prev_openmin = prev->openmin;
+		__entry->prev_openmax = prev->openmax;
+		__entry->prev_integer = prev->integer;
+		__entry->prev_empty = prev->empty;
+		__entry->curr_min = curr->min;
+		__entry->curr_max = curr->max;
+		__entry->curr_openmin = curr->openmin;
+		__entry->curr_openmax = curr->openmax;
+		__entry->curr_integer = curr->integer;
+		__entry->curr_empty = curr->empty;
+	),
+	TP_printk("%d,%d,%d,%d %03d/%03d %s %d %d %s%u %u%s %d %d %s%u %u%s",
+		  __entry->card,
+		  __entry->device,
+		  __entry->subdevice,
+		  __entry->direction,
+		  __entry->index,
+		  __entry->total,
+		  __print_symbolic(__entry->type, hw_param_labels),
+		  __entry->prev_empty,
+		  __entry->prev_integer,
+		  __entry->prev_openmin ? "(" : "[",
+		  __entry->prev_min,
+		  __entry->prev_max,
+		  __entry->prev_openmax ? ")" : "]",
+		  __entry->curr_empty,
+		  __entry->curr_integer,
+		  __entry->curr_openmin ? "(" : "[",
+		  __entry->curr_min,
+		  __entry->curr_max,
+		  __entry->curr_openmax ? ")" : "]"
+	)
+);
+
+#endif /* _PCM_PARAMS_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE pcm_param_trace
+#include <trace/define_trace.h>