ALSA: add/change some comments describing function return values

script/kernel-doc reports the following type of warnings (when run in verbose
mode):

Warning(sound/core/init.c:152): No description found for return value of
'snd_card_create'

To fix that:
- add missing descriptions of function return values
- use "Return:" sections to describe those return values

Along the way:
- complete some descriptions
- fix some typos

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 23 insertions, 18 deletions

diff --git a/sound/core/control.c b/sound/core/control.c
index 8c7c2c9bba6..d8aa206e8bd 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -190,7 +190,7 @@ EXPORT_SYMBOL(snd_ctl_notify);
  * Allocates a new struct snd_kcontrol instance and copies the given template 
  * to the new instance. It does not copy volatile data (access).
  *
- * Returns the pointer of the new instance, or NULL on failure.
+ * Return: The pointer of the new instance, or %NULL on failure.
  */
 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 					unsigned int access)
@@ -224,7 +224,7 @@ static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
  * template.  When the access field of ncontrol is 0, it's assumed as
  * READWRITE access. When the count field is 0, it's assumes as one.
  *
- * Returns the pointer of the newly generated instance, or NULL on failure.
+ * Return: The pointer of the newly generated instance, or %NULL on failure.
  */
 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 				  void *private_data)
@@ -322,9 +322,10 @@ static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
  * snd_ctl_new1() to the given card. Assigns also an unique
  * numid used for fast search.
  *
- * Returns zero if successful, or a negative error code on failure.
- *
  * It frees automatically the control which cannot be added.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ *
  */
 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 {
@@ -380,9 +381,9 @@ EXPORT_SYMBOL(snd_ctl_add);
  * and the add_on_replace flag is set, the control is added.  If the
  * control exists, it is destroyed first.
  *
- * Returns zero if successful, or a negative error code on failure.
- *
  * It frees automatically the control which cannot be added or replaced.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 		    bool add_on_replace)
@@ -442,8 +443,8 @@ EXPORT_SYMBOL(snd_ctl_replace);
  * Removes the control from the card and then releases the instance.
  * You don't need to call snd_ctl_free_one(). You must be in
  * the write lock - down_write(&card->controls_rwsem).
- * 
- * Returns 0 if successful, or a negative error code on failure.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
  */
 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 {
@@ -470,8 +471,8 @@ EXPORT_SYMBOL(snd_ctl_remove);
  *
  * Finds the control instance with the given id, removes it from the
  * card list and releases it.
- * 
- * Returns 0 if successful, or a negative error code on failure.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
  */
 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 {
@@ -498,8 +499,8 @@ EXPORT_SYMBOL(snd_ctl_remove_id);
  *
  * Finds the control instance with the given id, removes it from the
  * card list and releases it.
- * 
- * Returns 0 if successful, or a negative error code on failure.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
  */
 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 				   struct snd_ctl_elem_id *id)
@@ -541,7 +542,7 @@ error:
  * Finds the control instance with the given id, and activate or
  * inactivate the control together with notification, if changed.
  *
- * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
+ * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
  */
 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 			int active)
@@ -587,7 +588,7 @@ EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
  * Finds the control with the old id from the card, and replaces the
  * id with the new one.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 		      struct snd_ctl_elem_id *dst_id)
@@ -616,10 +617,11 @@ EXPORT_SYMBOL(snd_ctl_rename_id);
  *
  * Finds the control instance with the given number-id from the card.
  *
- * Returns the pointer of the instance if found, or NULL if not.
- *
  * The caller must down card->controls_rwsem before calling this function
  * (if the race condition can happen).
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ *
  */
 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 {
@@ -643,10 +645,11 @@ EXPORT_SYMBOL(snd_ctl_find_numid);
  *
  * Finds the control instance with the given id from the card.
  *
- * Returns the pointer of the instance if found, or NULL if not.
- *
  * The caller must down card->controls_rwsem before calling this function
  * (if the race condition can happen).
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ *
  */
 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 				     struct snd_ctl_elem_id *id)
@@ -1710,6 +1713,8 @@ EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
  * Sets all required fields in @info to their appropriate values.
  * If the control's accessibility is not the default (readable and writable),
  * the caller has to fill @info->access.
+ *
+ * Return: Zero.
  */
 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
 		      unsigned int items, const char *const names[])