ASoC: soc-cache: Add trace event for snd_soc_cache_sync()

This patch makes it easy to see when the syncing process begins and
ends.  You can also enable the snd_soc_reg_write tracepoint to see
which registers are being synced.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/trace/events/asoc.h

@@ -229,6 +229,31 @@ TRACE_EVENT(snd_soc_jack_notify,
 	TP_printk("jack=%s %x", __get_str(name), (int)__entry->val)
 );
 
+TRACE_EVENT(snd_soc_cache_sync,
+
+	TP_PROTO(struct snd_soc_codec *codec, const char *type,
+		 const char *status),
+
+	TP_ARGS(codec, type, status),
+
+	TP_STRUCT__entry(
+		__string(	name,		codec->name	)
+		__string(	status,		status		)
+		__string(	type,		type		)
+		__field(	int,		id		)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, codec->name);
+		__assign_str(status, status);
+		__assign_str(type, type);
+		__entry->id = codec->id;
+	),
+
+	TP_printk("codec=%s.%d type=%s status=%s", __get_str(name),
+		  (int)__entry->id, __get_str(type), __get_str(status))
+);
+
 #endif /* _TRACE_ASOC_H */
 
 /* This part must be outside protection */

sound/soc/soc-cache.c

@@ -18,6 +18,8 @@
 #include <linux/bitmap.h>
 #include <linux/rbtree.h>
 
+#include <trace/events/asoc.h>
+
 static unsigned int snd_soc_4_12_read(struct snd_soc_codec *codec,
 				     unsigned int reg)
 {
@@ -1601,18 +1603,26 @@ EXPORT_SYMBOL_GPL(snd_soc_cache_write);
 int snd_soc_cache_sync(struct snd_soc_codec *codec)
 {
 	int ret;
+	const char *name;
 
 	if (!codec->cache_sync) {
 		return 0;
 	}
 
+	if (codec->cache_ops->name)
+		name = codec->cache_ops->name;
+	else
+		name = "unknown";
+
 	if (codec->cache_ops && codec->cache_ops->sync) {
 		if (codec->cache_ops->name)
 			dev_dbg(codec->dev, "Syncing %s cache for %s codec\n",
 				codec->cache_ops->name, codec->name);
+		trace_snd_soc_cache_sync(codec, name, "start");
 		ret = codec->cache_ops->sync(codec);
 		if (!ret)
 			codec->cache_sync = 0;
+		trace_snd_soc_cache_sync(codec, name, "end");
 		return ret;
 	}