ASoC: Remove locking in snd_soc_{new, free}_ac97_codec()

Commit Message

Lars-Peter Clausen Sept. 22, 2014, 10:56 p.m. UTC

snd_soc_new_ac97_codec() and snd_soc_free_ac97_codec() are called from
within a CODEC's probe() and remove() callbacks. Those will not run
concurrently against each other for the same CODEC instance, hence it is not
necessary to protect the two functions with a mutex.

This removes the last user in the ASoC core of the snd_soc_codec mutex field
and will allow us to eventually remove it.

Signed-off-by: Lars-Peter Clausen <[e-mail]>
---
 sound/soc/soc-core.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

Comments

Mark Brown Sept. 23, 2014, 1:20 a.m. UTC | #1

On Tue, Sep 23, 2014 at 12:56:28AM +0200, Lars-Peter Clausen wrote:
> snd_soc_new_ac97_codec() and snd_soc_free_ac97_codec() are called from
> within a CODEC's probe() and remove() callbacks. Those will not run
> concurrently against each other for the same CODEC instance, hence it is not
> necessary to protect the two functions with a mutex.

Applied, thanks.

Patch

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 889f4e3..5289984 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2107,13 +2107,9 @@  static struct platform_driver soc_driver = {
 int snd_soc_new_ac97_codec(struct snd_soc_codec *codec,
 	struct snd_ac97_bus_ops *ops, int num)
 {
-	mutex_lock(&codec->mutex);
-
 	codec->ac97 = kzalloc(sizeof(struct snd_ac97), GFP_KERNEL);
-	if (codec->ac97 == NULL) {
-		mutex_unlock(&codec->mutex);
+	if (codec->ac97 == NULL)
 		return -ENOMEM;
-	}
 
 	codec->ac97->bus = kzalloc(sizeof(struct snd_ac97_bus), GFP_KERNEL);
 	if (codec->ac97->bus == NULL) {
@@ -2132,7 +2128,6 @@  int snd_soc_new_ac97_codec(struct snd_soc_codec *codec,
 	 */
 	codec->ac97_created = 1;
 
-	mutex_unlock(&codec->mutex);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_new_ac97_codec);
@@ -2302,7 +2297,6 @@  EXPORT_SYMBOL_GPL(snd_soc_set_ac97_ops_of_reset);
  */
 void snd_soc_free_ac97_codec(struct snd_soc_codec *codec)
 {
-	mutex_lock(&codec->mutex);
 #ifdef CONFIG_SND_SOC_AC97_BUS
 	soc_unregister_ac97_codec(codec);
 #endif
@@ -2310,7 +2304,6 @@  void snd_soc_free_ac97_codec(struct snd_soc_codec *codec)
 	kfree(codec->ac97);
 	codec->ac97 = NULL;
 	codec->ac97_created = 0;
-	mutex_unlock(&codec->mutex);
 }
 EXPORT_SYMBOL_GPL(snd_soc_free_ac97_codec);