[alsa-devel] [PATCH v2 1/8] ASoC: dapm: Only mark paths dirty when the connection status changed

[Lars-Peter Clausen]

Rework soc_dapm_{mixer,mux}_update_power() to only mark a path dirty if the
connect state if the path has actually changed. This avoids unnecessary
power state checks for the widgets involved.

Also factor out the common code that is involved in this into a helper
function.

Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
---
Changes since v1:
	* Drop return type from soc_dapm_connect_path() since it is currently
	  unused.
	* Change '/**' to '/*' for static function documentation to prevent it
	  from showing up in the generated public API documentation
---
 sound/soc/soc-dapm.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index f03e0cf..116d443 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1925,12 +1925,31 @@ static inline void dapm_debugfs_cleanup(struct snd_soc_dapm_context *dapm)
 
 #endif
 
+/*
+ * soc_dapm_connect_path() - Connects or disconnects a path
+ * @path: The path to update
+ * @connect: The new connect state of the path. True if the path is connected,
+ *  false if it is disconneted.
+ * @reason: The reason why the path changed (for debugging only)
+ */
+static void soc_dapm_connect_path(struct snd_soc_dapm_path *path,
+	bool connect, const char *reason)
+{
+	if (path->connect == connect)
+		return;
+
+	path->connect = connect;
+	dapm_mark_dirty(path->source, reason);
+	dapm_mark_dirty(path->sink, reason);
+}
+
 /* test and update the power status of a mux widget */
 static int soc_dapm_mux_update_power(struct snd_soc_card *card,
 				 struct snd_kcontrol *kcontrol, int mux, struct soc_enum *e)
 {
 	struct snd_soc_dapm_path *path;
 	int found = 0;
+	bool connect;
 
 	lockdep_assert_held(&card->dapm_mutex);
 
@@ -1941,16 +1960,12 @@ static int soc_dapm_mux_update_power(struct snd_soc_card *card,
 
 		found = 1;
 		/* we now need to match the string in the enum to the path */
-		if (!(strcmp(path->name, e->texts[mux]))) {
-			path->connect = 1; /* new connection */
-			dapm_mark_dirty(path->source, "mux connection");
-		} else {
-			if (path->connect)
-				dapm_mark_dirty(path->source,
-						"mux disconnection");
-			path->connect = 0; /* old connection must be powered down */
-		}
-		dapm_mark_dirty(path->sink, "mux change");
+		if (!(strcmp(path->name, e->texts[mux])))
+			connect = true;
+		else
+			connect = false;
+
+		soc_dapm_connect_path(path, connect, "mux update");
 	}
 
 	if (found)
@@ -1989,9 +2004,7 @@ static int soc_dapm_mixer_update_power(struct snd_soc_card *card,
 	/* find dapm widget path assoc with kcontrol */
 	dapm_kcontrol_for_each_path(path, kcontrol) {
 		found = 1;
-		path->connect = connect;
-		dapm_mark_dirty(path->source, "mixer connection");
-		dapm_mark_dirty(path->sink, "mixer update");
+		soc_dapm_connect_path(path, connect, "mixer update");
 	}
 
 	if (found)
-- 
1.8.0