[PATCH 1/3] ALSA: control: Introduce snd_ctl_find_id_mixer_locked()

From: Richard Fitzgerald
Date: Mon Mar 25 2024 - 11:32:10 EST


Adds wrapper function snd_ctl_find_id_mixer_locked(). This is
identical to snd_ctl_find_id_mixer() except that it can be called
from code that is already holding controls_rwsem.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
include/sound/control.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/include/sound/control.h b/include/sound/control.h
index 9a4f4f7138da..c1659036c4a7 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -167,6 +167,29 @@ snd_ctl_find_id_mixer(struct snd_card *card, const char *name)
return snd_ctl_find_id(card, &id);
}

+/**
+ * snd_ctl_find_id_mixer_locked - find the control instance with the given name string
+ * @card: the card instance
+ * @name: the name string
+ *
+ * Finds the control instance with the given name and
+ * @SNDRV_CTL_ELEM_IFACE_MIXER. Other fields are set to zero.
+ *
+ * This is merely a wrapper to snd_ctl_find_id_locked().
+ * The caller must down card->controls_rwsem before calling this function.
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ */
+static inline struct snd_kcontrol *
+snd_ctl_find_id_mixer_locked(struct snd_card *card, const char *name)
+{
+ struct snd_ctl_elem_id id = {};
+
+ id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+ strscpy(id.name, name, sizeof(id.name));
+ return snd_ctl_find_id_locked(card, &id);
+}
+
int snd_ctl_create(struct snd_card *card);

int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
--
2.39.2