[RFC 2/4] alsa: add locked variant for snd_ctl_remove_id

[Vaibhav Agarwal <vaibhav.agarwal@linaro.org>]

While removing kcontrols due to dynamic dai_link/codec removal,
mutex/semaphore for soc-card/sound card is already acquired.
Thus, added lock already acquired variant for ctl_remove_id.

Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
---
 include/sound/control.h |  1 +
 sound/core/control.c    | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/sound/control.h b/include/sound/control.h
index 21d047f..8faea10 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -125,6 +125,7 @@ int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
 int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
+int snd_ctl_remove_id_locked(struct snd_card *card, struct snd_ctl_elem_id *id);
 int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 			int active);
diff --git a/sound/core/control.c b/sound/core/control.c
index a85d455..dca1998 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -530,6 +530,29 @@ int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 EXPORT_SYMBOL(snd_ctl_remove_id);
 
 /**
+ * snd_ctl_remove_id_locked - remove the control of the given id and release it
+ * @card: the card instance
+ * @id: the control id to remove
+ *
+ * Finds the control instance with the given id, removes it from the
+ * card list and releases it.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
+ */
+int snd_ctl_remove_id_locked(struct snd_card *card, struct snd_ctl_elem_id *id)
+{
+	struct snd_kcontrol *kctl;
+	int ret;
+
+	kctl = snd_ctl_find_id(card, id);
+	if (kctl == NULL)
+		return -ENOENT;
+	ret = snd_ctl_remove(card, kctl);
+	return ret;
+}
+EXPORT_SYMBOL(snd_ctl_remove_id_locked);
+
+/**
  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
  * @file: active control handle
  * @id: the control id to remove
-- 
2.1.4