2 files changed, 19 insertions, 0 deletions

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 4fb079e14e16..5c3bce83f28a 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -442,6 +442,7 @@ struct snd_soc_codec {
         unsigned int suspended:1; /* Codec is in suspend PM state */
         unsigned int probed:1; /* Codec has been probed */
         unsigned int ac97_registered:1; /* Codec has been AC97 registered */
+        unsigned int ac97_created:1; /* Codec has been created by SoC */
         unsigned int sysfs_registered:1; /* codec has been sysfs registered */
 
         /* codec IO */
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 8751efdea119..7d22b5d5bc0d 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1497,6 +1497,16 @@ static int soc_register_ac97_dai_link(struct snd_soc_pcm_runtime *rtd)
          * for the generic AC97 subsystem.
          */
         if (rtd->codec_dai->driver->ac97_control && !rtd->codec->ac97_registered) {
+                /*
+                 * It is possible that the AC97 device is already registered to
+                 * the device subsystem. This happens when the device is created
+                 * via snd_ac97_mixer(). Currently only SoC codec that does so
+                 * is the generic AC97 glue but others migh emerge.
+                 *
+                 * In those cases we don't try to register the device again.
+                 */
+                if (!rtd->codec->ac97_created)
+                        return 0;
 
                 ret = soc_ac97_dev_register(rtd->codec);
                 if (ret < 0) {
@@ -1812,6 +1822,13 @@ int snd_soc_new_ac97_codec(struct snd_soc_codec *codec,
 
         codec->ac97->bus->ops = ops;
         codec->ac97->num = num;
+
+        /*
+         * Mark the AC97 device to be created by us. This way we ensure that the
+         * device will be registered with the device subsystem later on.
+         */
+        codec->ac97_created = 1;
+
         mutex_unlock(&codec->mutex);
         return 0;
 }
@@ -1832,6 +1849,7 @@ void snd_soc_free_ac97_codec(struct snd_soc_codec *codec)
         kfree(codec->ac97->bus);
         kfree(codec->ac97);
         codec->ac97 = NULL;
+        codec->ac97_created = 0;
         mutex_unlock(&codec->mutex);
 }
 EXPORT_SYMBOL_GPL(snd_soc_free_ac97_codec);