[PATCH] ASoC: soc-core: call snd_soc_unbind_card() under mutex_lock;

[Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>]

From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>

commit 34ac3c3eb8f0c07 ("ASoC: core: lock client_mutex while removing
link components") added mutex_lock() at soc_remove_link_components().

Is is called from snd_soc_unbind_card()

	snd_soc_unbind_card()
=>		soc_remove_link_components()
		soc_cleanup_card_resources()
			soc_remove_dai_links()
=>				soc_remove_link_components()

And, there are 2 way to call it.

(1)
	snd_soc_unregister_component()
**		mutex_lock()
			snd_soc_component_del_unlocked()
=>				snd_soc_unbind_card()
**		mutex_unlock()

(2)
	snd_soc_unregister_card()
=>		snd_soc_unbind_card()

(1) case is already using mutex_lock() when it calles
snd_soc_unbind_card(), thus, we will get lockdep warning.
We need mutex_lock() under snd_soc_unregister_card()
instead of snd_remove_link_components().

Fixes: 34ac3c3eb8f0c07 ("ASoC: core: lock client_mutex while removing link components")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
 sound/soc/soc-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 94a36ee..1679990 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1018,14 +1018,12 @@ static void soc_remove_link_components(struct snd_soc_card *card,
 	struct snd_soc_component *component;
 	struct snd_soc_rtdcom_list *rtdcom;
 
-	mutex_lock(&client_mutex);
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
 
 		if (component->driver->remove_order == order)
 			soc_remove_component(component);
 	}
-	mutex_unlock(&client_mutex);
 }
 
 static void soc_remove_dai_links(struct snd_soc_card *card)
@@ -2774,7 +2772,9 @@ static void snd_soc_unbind_card(struct snd_soc_card *card, bool unregister)
  */
 int snd_soc_unregister_card(struct snd_soc_card *card)
 {
+	mutex_lock(&client_mutex);
 	snd_soc_unbind_card(card, true);
+	mutex_unlock(&client_mutex);
 	dev_dbg(card->dev, "ASoC: Unregistered card '%s'\n", card->name);
 
 	return 0;
-- 
2.7.4

_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel