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

[Lars-Peter Clausen]

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 <***@metafoo.de>
---
sound/soc/soc-core.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

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);

[Mark Brown]

Post by Lars-Peter Clausen
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.