ASoC: dapm: Add a update parameter to snd_soc_dapm_{mux,mixer}_update_power

In order to avoid race conditions the assignment of dapm->update should happen
while card->dapm_mutex is being held. To allow CODEC drivers to run a register
update when using snd_soc_dapm_mux_update_power() or
snd_soc_dapm_mixer_update_power() add a update parameter to these two functions.
The update parameter will be assigned to dapm->update while card->dapm_mutex is
locked.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc-dapm.h

@@ -333,6 +333,7 @@ struct snd_soc_dapm_route;
 struct snd_soc_dapm_context;
 struct regulator;
 struct snd_soc_dapm_widget_list;
+struct snd_soc_dapm_update;
 
 int dapm_reg_event(struct snd_soc_dapm_widget *w,
 		   struct snd_kcontrol *kcontrol, int event);
@@ -392,9 +393,11 @@ void snd_soc_dapm_shutdown(struct snd_soc_card *card);
 
 /* external DAPM widget events */
 int snd_soc_dapm_mixer_update_power(struct snd_soc_dapm_context *dapm,
-		struct snd_kcontrol *kcontrol, int connect);
+		struct snd_kcontrol *kcontrol, int connect,
+		struct snd_soc_dapm_update *update);
 int snd_soc_dapm_mux_update_power(struct snd_soc_dapm_context *dapm,
-		struct snd_kcontrol *kcontrol, int mux, struct soc_enum *e);
+		struct snd_kcontrol *kcontrol, int mux, struct soc_enum *e,
+		struct snd_soc_dapm_update *update);
 
 /* dapm sys fs - used by the core */
 int snd_soc_dapm_sys_add(struct device *dev);

sound/soc/soc-dapm.c

@@ -1982,13 +1982,16 @@ static int soc_dapm_mux_update_power(struct snd_soc_dapm_context *dapm,
 }
 
 int snd_soc_dapm_mux_update_power(struct snd_soc_dapm_context *dapm,
-	struct snd_kcontrol *kcontrol, int mux, struct soc_enum *e)
+	struct snd_kcontrol *kcontrol, int mux, struct soc_enum *e,
+	struct snd_soc_dapm_update *update)
 {
 	struct snd_soc_card *card = dapm->card;
 	int ret;
 
 	mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
+	dapm->update = update;
 	ret = soc_dapm_mux_update_power(dapm, kcontrol, mux, e);
+	dapm->update = NULL;
 	mutex_unlock(&card->dapm_mutex);
 	if (ret > 0)
 		soc_dpcm_runtime_update(card);
@@ -2022,13 +2025,16 @@ static int soc_dapm_mixer_update_power(struct snd_soc_dapm_context *dapm,
 }
 
 int snd_soc_dapm_mixer_update_power(struct snd_soc_dapm_context *dapm,
-	struct snd_kcontrol *kcontrol, int connect)
+	struct snd_kcontrol *kcontrol, int connect,
+	struct snd_soc_dapm_update *update)
 {
 	struct snd_soc_card *card = dapm->card;
 	int ret;
 
 	mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
+	dapm->update = update;
 	ret = soc_dapm_mixer_update_power(dapm, kcontrol, connect);
+	dapm->update = NULL;
 	mutex_unlock(&card->dapm_mutex);
 	if (ret > 0)
 		soc_dpcm_runtime_update(card);