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>

3 files changed, 19 insertions, 11 deletions

diff --git a/include/sound/control.h b/include/sound/control.h
index 8332e865c75..34bc93d80d5 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -189,7 +189,6 @@ int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
  *
  * Add a virtual slave control to the given master element created via
  * snd_ctl_create_virtual_master() beforehand.
- * Returns zero if successful or a negative error code.
  *
  * All slaves must be the same type (returning the same information
  * via info callback).  The function doesn't check it, so it's your
@@ -199,6 +198,8 @@ int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
  * at most two channels,
  * logarithmic volume control (dB level) thus no linear volume,
  * master can only attenuate the volume without gain
+ *
+ * Return: Zero if successful or a negative error code.
  */
 static inline int
 snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
@@ -219,6 +220,8 @@ snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
  * When the control peeks the hardware values directly and the value
  * can be changed by other means than the put callback of the element,
  * this function should be used to keep the value always up-to-date.
+ *
+ * Return: Zero if successful or a negative error code.
  */
 static inline int
 snd_ctl_add_slave_uncached(struct snd_kcontrol *master,
diff --git a/include/sound/core.h b/include/sound/core.h
index a63680b9819..5bfe5136441 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -229,7 +229,7 @@ int snd_register_device_for_dev(int type, struct snd_card *card,
  * This function uses the card's device pointer to link to the
  * correct &struct device.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 static inline int snd_register_device(int type, struct snd_card *card, int dev,
 				      const struct file_operations *f_ops,
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 45c1981c9ca..aa7b0a8385c 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -659,7 +659,7 @@ static inline snd_pcm_sframes_t snd_pcm_capture_hw_avail(struct snd_pcm_runtime
  *
  * Checks whether enough free space is available on the playback buffer.
  *
- * Returns non-zero if available, or zero if not.
+ * Return: Non-zero if available, or zero if not.
  */
 static inline int snd_pcm_playback_ready(struct snd_pcm_substream *substream)
 {
@@ -673,7 +673,7 @@ static inline int snd_pcm_playback_ready(struct snd_pcm_substream *substream)
  *
  * Checks whether enough capture data is available on the capture buffer.
  *
- * Returns non-zero if available, or zero if not.
+ * Return: Non-zero if available, or zero if not.
  */
 static inline int snd_pcm_capture_ready(struct snd_pcm_substream *substream)
 {
@@ -685,10 +685,10 @@ static inline int snd_pcm_capture_ready(struct snd_pcm_substream *substream)
  * snd_pcm_playback_data - check whether any data exists on the playback buffer
  * @substream: the pcm substream instance
  *
- * Checks whether any data exists on the playback buffer. If stop_threshold
- * is bigger or equal to boundary, then this function returns always non-zero.
+ * Checks whether any data exists on the playback buffer.
  *
- * Returns non-zero if exists, or zero if not.
+ * Return: Non-zero if any data exists, or zero if not. If stop_threshold
+ * is bigger or equal to boundary, then this function returns always non-zero.
  */
 static inline int snd_pcm_playback_data(struct snd_pcm_substream *substream)
 {
@@ -705,7 +705,7 @@ static inline int snd_pcm_playback_data(struct snd_pcm_substream *substream)
  *
  * Checks whether the playback buffer is empty.
  *
- * Returns non-zero if empty, or zero if not.
+ * Return: Non-zero if empty, or zero if not.
  */
 static inline int snd_pcm_playback_empty(struct snd_pcm_substream *substream)
 {
@@ -719,7 +719,7 @@ static inline int snd_pcm_playback_empty(struct snd_pcm_substream *substream)
  *
  * Checks whether the capture buffer is empty.
  *
- * Returns non-zero if empty, or zero if not.
+ * Return: Non-zero if empty, or zero if not.
  */
 static inline int snd_pcm_capture_empty(struct snd_pcm_substream *substream)
 {
@@ -852,7 +852,7 @@ int snd_pcm_format_big_endian(snd_pcm_format_t format);
  * snd_pcm_format_cpu_endian - Check the PCM format is CPU-endian
  * @format: the format to check
  *
- * Returns 1 if the given PCM format is CPU-endian, 0 if
+ * Return: 1 if the given PCM format is CPU-endian, 0 if
  * opposite, or a negative error code if endian not specified.
  */
 int snd_pcm_format_cpu_endian(snd_pcm_format_t format);
@@ -963,7 +963,7 @@ struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
  * contiguous in kernel virtual space, but not in physical memory.  Use this
  * if the buffer is accessed by kernel code but not by device DMA.
  *
- * Returns 1 if the buffer was changed, 0 if not changed, or a negative error
+ * Return: 1 if the buffer was changed, 0 if not changed, or a negative error
  * code.
  */
 static int snd_pcm_lib_alloc_vmalloc_buffer
@@ -975,6 +975,9 @@ static int snd_pcm_lib_alloc_vmalloc_buffer
  *
  * This function works like snd_pcm_lib_alloc_vmalloc_buffer(), but uses
  * vmalloc_32(), i.e., the pages are allocated from 32-bit-addressable memory.
+ *
+ * Return: 1 if the buffer was changed, 0 if not changed, or a negative error
+ * code.
  */
 static int snd_pcm_lib_alloc_vmalloc_32_buffer
 			(struct snd_pcm_substream *substream, size_t size);
@@ -1070,6 +1073,8 @@ const char *snd_pcm_format_name(snd_pcm_format_t format);
 /**
  * snd_pcm_stream_str - Get a string naming the direction of a stream
  * @substream: the pcm substream instance
+ *
+ * Return: A string naming the direction of the stream.
  */
 static inline const char *snd_pcm_stream_str(struct snd_pcm_substream *substream)
 {