4 files changed, 8 insertions, 7 deletions
diff --git a/src/mixer/alsa_mixer.c b/src/mixer/alsa_mixer.c
index 7dafd22cc..d0cfdd5a2 100644
--- a/src/mixer/alsa_mixer.c
+++ b/src/mixer/alsa_mixer.c
@@ -43,7 +43,7 @@ alsa_mixer_finish(struct mixer_data *data)
 }
 
 static void
-alsa_mixer_configure(struct mixer_data *data, struct config_param *param)
+alsa_mixer_configure(struct mixer_data *data, const struct config_param *param)
 {
 	struct alsa_mixer *am = (struct alsa_mixer *)data;
 	const char *value;
@@ -149,7 +149,7 @@ alsa_mixer_control(struct mixer_data *data, int cmd, void *arg)
 	struct alsa_mixer *am = (struct alsa_mixer *)data;
 	switch (cmd) {
 	case AC_MIXER_CONFIGURE:
-		alsa_mixer_configure(data, (struct config_param *)arg);
+		alsa_mixer_configure(data, (const struct config_param *)arg);
 		if (am->handle)
 			alsa_mixer_close(data);
 		return true;
diff --git a/src/mixer/oss_mixer.c b/src/mixer/oss_mixer.c
index 5e3b65f46..ed370483d 100644
--- a/src/mixer/oss_mixer.c
+++ b/src/mixer/oss_mixer.c
@@ -47,7 +47,7 @@ oss_mixer_finish(struct mixer_data *data)
 }
 
 static void
-oss_mixer_configure(struct mixer_data *data, struct config_param *param)
+oss_mixer_configure(struct mixer_data *data, const struct config_param *param)
 {
 	struct oss_mixer *om = (struct oss_mixer *) data;
 	const char *value;
@@ -140,7 +140,7 @@ oss_mixer_control(struct mixer_data *data, int cmd, void *arg)
 	struct oss_mixer *om = (struct oss_mixer *) data;
 	switch (cmd) {
 	case AC_MIXER_CONFIGURE:
-		oss_mixer_configure(data, (struct config_param *)arg);
+		oss_mixer_configure(data, (const struct config_param *)arg);
 		if (om->device_fd >= 0)
 			oss_mixer_close(data);
 		return true;
diff --git a/src/mixer_api.c b/src/mixer_api.c
index cb493aa0a..51df10d78 100644
--- a/src/mixer_api.c
+++ b/src/mixer_api.c
@@ -20,7 +20,7 @@ void mixer_finish(struct mixer *mixer)
 	mixer->plugin = NULL;
 }
 
-void mixer_configure(struct mixer *mixer, struct config_param *param)
+void mixer_configure(struct mixer *mixer, const struct config_param *param)
 {
 	assert(mixer != NULL && mixer->plugin != NULL);
 	mixer->plugin->configure(mixer->data, param);
diff --git a/src/mixer_api.h b/src/mixer_api.h
index 61f6c06f2..55aa7684c 100644
--- a/src/mixer_api.h
+++ b/src/mixer_api.h
@@ -28,7 +28,8 @@ struct mixer_plugin {
         /**
 	 * Setup and configure mixer
          */
-	void (*configure)(struct mixer_data *data, struct config_param *param);
+	void (*configure)(struct mixer_data *data,
+			  const struct config_param *param);
 
         /**
     	 * Open mixer device
@@ -53,7 +54,7 @@ struct mixer {
 
 void mixer_init(struct mixer *mixer, struct mixer_plugin *plugin);
 void mixer_finish(struct mixer *mixer);
-void mixer_configure(struct mixer *mixer, struct config_param *param);
+void mixer_configure(struct mixer *mixer, const struct config_param *param);
 bool mixer_open(struct mixer *mixer);
 bool mixer_control(struct mixer *mixer, int cmd, void *arg);
 void mixer_close(struct mixer *mixer);