Commit eb7c06e8 authored by Yacine Belkadi's avatar Yacine Belkadi Committed by Takashi Iwai
Browse files

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: default avatarYacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent a817650e

include/sound/control.h

+4 −1
Original line number Diff line number Diff line
@@ -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,

include/sound/core.h

+1 −1
Original line number Diff line number Diff line
@@ -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,

include/sound/pcm.h

+14 −9
Original line number Diff line number Diff line
@@ -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)

{

sound/core/control.c

+23 −18
Original line number Diff line number Diff line
@@ -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)
@@ -443,7 +444,7 @@ EXPORT_SYMBOL(snd_ctl_replace); 
 * 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)

{
@@ -471,7 +472,7 @@ 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)

{
@@ -499,7 +500,7 @@ 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[])

sound/core/device.c

+4 −4
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ 
 * The data pointer plays a role as the identifier, too, so the

 * pointer address must be unique and unchanged.

 *

 * Returns zero if successful, or a negative error code on failure.

 * Return: Zero if successful, or a negative error code on failure.

 */

int snd_device_new(struct snd_card *card, snd_device_type_t type,

		   void *device_data, struct snd_device_ops *ops)
@@ -73,7 +73,7 @@ EXPORT_SYMBOL(snd_device_new); 
 * callbacks, dev_disconnect and dev_free, corresponding to the state.

 * Then release the device.

 *

 * Returns zero if successful, or a negative error code on failure or if the

 * Return: Zero if successful, or a negative error code on failure or if the

 * device not found.

 */

int snd_device_free(struct snd_card *card, void *device_data)
@@ -116,7 +116,7 @@ EXPORT_SYMBOL(snd_device_free); 
 *

 * Usually called from snd_card_disconnect().

 *

 * Returns zero if successful, or a negative error code on failure or if the

 * Return: Zero if successful, or a negative error code on failure or if the

 * device not found.

 */

int snd_device_disconnect(struct snd_card *card, void *device_data)
@@ -151,7 +151,7 @@ int snd_device_disconnect(struct snd_card *card, void *device_data) 
 * but it can be called later if any new devices are created after

 * invocation of snd_card_register().

 *

 * Returns zero if successful, or a negative error code on failure or if the

 * Return: Zero if successful, or a negative error code on failure or if the

 * device not found.

 */

int snd_device_register(struct snd_card *card, void *device_data)

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