[alsa-devel] [PATCH] ASoC: wm2000: Lock state machine updates

[Mark Brown]

Need to ensure we don't get confused by simultaneous updates.

Signed-off-by: Mark Brown <broonie at opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm2000.c |   31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/wm2000.c b/sound/soc/codecs/wm2000.c
index 655f43e..4d809ab 100644
--- a/sound/soc/codecs/wm2000.c
+++ b/sound/soc/codecs/wm2000.c
@@ -77,6 +77,8 @@ struct wm2000_priv {
 
 	int anc_download_size;
 	char *anc_download;
+
+	struct mutex lock;
 };
 
 static int wm2000_write(struct i2c_client *i2c, unsigned int reg,
@@ -614,13 +616,20 @@ static int wm2000_anc_mode_put(struct snd_kcontrol *kcontrol,
 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
 	struct wm2000_priv *wm2000 = dev_get_drvdata(codec->dev);
 	int anc_active = ucontrol->value.enumerated.item[0];
+	int ret;
 
 	if (anc_active > 1)
 		return -EINVAL;
 
+	mutex_lock(&wm2000->lock);
+
 	wm2000->anc_active = anc_active;
 
-	return wm2000_anc_set_mode(wm2000);
+	ret = wm2000_anc_set_mode(wm2000);
+
+	mutex_unlock(&wm2000->lock);
+
+	return ret;
 }
 
 static int wm2000_speaker_get(struct snd_kcontrol *kcontrol,
@@ -640,13 +649,20 @@ static int wm2000_speaker_put(struct snd_kcontrol *kcontrol,
 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
 	struct wm2000_priv *wm2000 = dev_get_drvdata(codec->dev);
 	int val = ucontrol->value.enumerated.item[0];
+	int ret;
 
 	if (val > 1)
 		return -EINVAL;
 
+	mutex_lock(&wm2000->lock);
+
 	wm2000->spk_ena = val;
 
-	return wm2000_anc_set_mode(wm2000);
+	ret = wm2000_anc_set_mode(wm2000);
+
+	mutex_unlock(&wm2000->lock);
+
+	return ret;
 }
 
 static const struct snd_kcontrol_new wm2000_controls[] = {
@@ -663,6 +679,9 @@ static int wm2000_anc_power_event(struct snd_soc_dapm_widget *w,
 {
 	struct snd_soc_codec *codec = w->codec;
 	struct wm2000_priv *wm2000 = dev_get_drvdata(codec->dev);
+	int ret;
+
+	mutex_lock(&wm2000->lock);
 
 	if (SND_SOC_DAPM_EVENT_ON(event))
 		wm2000->anc_eng_ena = 1;
@@ -670,7 +689,11 @@ static int wm2000_anc_power_event(struct snd_soc_dapm_widget *w,
 	if (SND_SOC_DAPM_EVENT_OFF(event))
 		wm2000->anc_eng_ena = 0;
 
-	return wm2000_anc_set_mode(wm2000);
+	ret = wm2000_anc_set_mode(wm2000);
+
+	mutex_unlock(&wm2000->lock);
+
+	return ret;
 }
 
 static const struct snd_soc_dapm_widget wm2000_dapm_widgets[] = {
@@ -800,6 +823,8 @@ static int wm2000_i2c_probe(struct i2c_client *i2c,
 		return -ENOMEM;
 	}
 
+	mutex_init(&wm2000->lock);
+
 	dev_set_drvdata(&i2c->dev, wm2000);
 
 	wm2000->regmap = devm_regmap_init_i2c(i2c, &wm2000_regmap);
-- 
1.7.10.4