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>

17 files changed, 164 insertions, 99 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[])
diff --git a/sound/core/device.c b/sound/core/device.c
index f03cb5444a5..df88defed17 100644
--- a/sound/core/device.c
+++ b/sound/core/device.c
@@ -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)
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index 3f7f6628cf7..d105073298c 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -356,7 +356,7 @@ static const struct file_operations snd_hwdep_f_ops =
  * The callbacks (hwdep->ops) must be set on the returned instance
  * after this call manually by the caller.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_hwdep_new(struct snd_card *card, char *id, int device,
 		  struct snd_hwdep **rhwdep)
diff --git a/sound/core/info.c b/sound/core/info.c
index 5bb97e7d325..db308dbc891 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -105,7 +105,7 @@ static int resize_info_buffer(struct snd_info_buffer *buffer,
  *
  * Outputs the string on the procfs buffer just like printf().
  *
- * Returns the size of output string.
+ * Return: The size of output string, or a negative error code.
  */
 int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
 {
@@ -694,7 +694,7 @@ int snd_info_card_free(struct snd_card *card)
  *
  * Reads one line from the buffer and stores the string.
  *
- * Returns zero if successful, or 1 if error or EOF.
+ * Return: Zero if successful, or 1 if error or EOF.
  */
 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 {
@@ -735,7 +735,7 @@ EXPORT_SYMBOL(snd_info_get_line);
  * Parses the original string and copy a token to the given
  * string buffer.
  *
- * Returns the updated pointer of the original string so that
+ * Return: The updated pointer of the original string so that
  * it can be used for the next call.
  */
 const char *snd_info_get_str(char *dest, const char *src, int len)
@@ -774,7 +774,7 @@ EXPORT_SYMBOL(snd_info_get_str);
  * Usually called from other functions such as
  * snd_info_create_card_entry().
  *
- * 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_info_entry *snd_info_create_entry(const char *name)
 {
@@ -803,7 +803,7 @@ static struct snd_info_entry *snd_info_create_entry(const char *name)
  *
  * Creates a new info entry and assigns it to the given module.
  *
- * Returns the pointer of the new instance, or NULL on failure.
+ * Return: The pointer of the new instance, or %NULL on failure.
  */
 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 					       const char *name,
@@ -827,7 +827,7 @@ EXPORT_SYMBOL(snd_info_create_module_entry);
  *
  * Creates a new info entry and assigns it to the given card.
  *
- * Returns the pointer of the new instance, or NULL on failure.
+ * Return: The pointer of the new instance, or %NULL on failure.
  */
 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 					     const char *name,
@@ -893,7 +893,7 @@ static int snd_info_dev_register_entry(struct snd_device *device)
  * For releasing this entry, use snd_device_free() instead of
  * snd_info_free_entry(). 
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_card_proc_new(struct snd_card *card, const char *name,
 		      struct snd_info_entry **entryp)
@@ -949,7 +949,7 @@ EXPORT_SYMBOL(snd_info_free_entry);
  *
  * Registers the proc info entry.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_info_register(struct snd_info_entry * entry)
 {
diff --git a/sound/core/init.c b/sound/core/init.c
index 7b012d15c2c..6ef06400dfc 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -144,7 +144,7 @@ static inline int init_info_for_card(struct snd_card *card)
  *  space for the driver to use freely.  The allocated struct is stored
  *  in the given card_ret pointer.
  *
- *  Returns zero if successful or a negative error code.
+ *  Return: Zero if successful or a negative error code.
  */
 int snd_card_create(int idx, const char *xid,
 		    struct module *module, int extra_size,
@@ -337,7 +337,7 @@ static const struct file_operations snd_shutdown_f_ops =
  *
  *  Disconnects all APIs from the file-operations (user space).
  *
- *  Returns zero, otherwise a negative error code.
+ *  Return: Zero, otherwise a negative error code.
  *
  *  Note: The current implementation replaces all active file->f_op with special
  *        dummy file operations (they do nothing except release).
@@ -415,7 +415,7 @@ EXPORT_SYMBOL(snd_card_disconnect);
  *  devices automatically.  That is, you don't have to release the devices
  *  by yourself.
  *
- *  Returns zero. Frees all associated devices and frees the control
+ *  Return: Zero. Frees all associated devices and frees the control
  *  interface associated to given soundcard.
  */
 static int snd_card_do_free(struct snd_card *card)
@@ -677,7 +677,7 @@ static struct device_attribute card_number_attrs =
  *  external accesses.  Thus, you should call this function at the end
  *  of the initialization of the card.
  *
- *  Returns zero otherwise a negative error code if the registration failed.
+ *  Return: Zero otherwise a negative error code if the registration failed.
  */
 int snd_card_register(struct snd_card *card)
 {
@@ -849,7 +849,7 @@ int __exit snd_card_info_done(void)
  *  This function adds the component id string to the supported list.
  *  The component can be referred from the alsa-lib.
  *
- *  Returns zero otherwise a negative error code.
+ *  Return: Zero otherwise a negative error code.
  */
   
 int snd_component_add(struct snd_card *card, const char *component)
@@ -883,7 +883,7 @@ EXPORT_SYMBOL(snd_component_add);
  *  This linked-list is used to keep tracking the connection state,
  *  and to avoid the release of busy resources by hotplug.
  *
- *  Returns zero or a negative error code.
+ *  Return: zero or a negative error code.
  */
 int snd_card_file_add(struct snd_card *card, struct file *file)
 {
@@ -920,7 +920,7 @@ EXPORT_SYMBOL(snd_card_file_add);
  *  called beforehand, it processes the pending release of
  *  resources.
  *
- *  Returns zero or a negative error code.
+ *  Return: Zero or a negative error code.
  */
 int snd_card_file_remove(struct snd_card *card, struct file *file)
 {
@@ -959,6 +959,8 @@ EXPORT_SYMBOL(snd_card_file_remove);
  *
  *  Waits until the power-state is changed.
  *
+ *  Return: Zero if successful, or a negative error code.
+ *
  *  Note: the power lock must be active before call.
  */
 int snd_power_wait(struct snd_card *card, unsigned int power_state)
diff --git a/sound/core/isadma.c b/sound/core/isadma.c
index c0f1208bb7d..e2b386156a4 100644
--- a/sound/core/isadma.c
+++ b/sound/core/isadma.c
@@ -81,7 +81,7 @@ EXPORT_SYMBOL(snd_dma_disable);
  * @dma: the dma number
  * @size: the dma transfer size
  *
- * Returns the current pointer in DMA tranfer buffer in bytes
+ * Return: The current pointer in DMA transfer buffer in bytes.
  */
 unsigned int snd_dma_pointer(unsigned long dma, unsigned int size)
 {
diff --git a/sound/core/jack.c b/sound/core/jack.c
index a06b1651fcb..b35fe7345c2 100644
--- a/sound/core/jack.c
+++ b/sound/core/jack.c
@@ -98,8 +98,8 @@ static int snd_jack_dev_register(struct snd_device *device)
  *
  * Creates a new jack object.
  *
- * Returns zero if successful, or a negative error code on failure.
- * On success jjack will be initialised.
+ * Return: Zero if successful, or a negative error code on failure.
+ * On success @jjack will be initialised.
  */
 int snd_jack_new(struct snd_card *card, const char *id, int type,
 		 struct snd_jack **jjack)
@@ -189,6 +189,8 @@ EXPORT_SYMBOL(snd_jack_set_parent);
  * using this abstraction.
  *
  * This function may only be called prior to registration of the jack.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
 		     int keytype)
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 69156923843..bdf826f4fe0 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -81,7 +81,7 @@ static inline void dec_snd_pages(int order)
  *
  * Allocates the physically contiguous pages with the given size.
  *
- * Returns the pointer of the buffer, or NULL if no enoguh memory.
+ * Return: The pointer of the buffer, or %NULL if no enough memory.
  */
 void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
 {
@@ -175,9 +175,9 @@ static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
  *
  * Calls the memory-allocator function for the corresponding
  * buffer type.
- * 
- * Returns zero if the buffer with the given size is allocated successfully,
- * other a negative value at error.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
  */
 int snd_dma_alloc_pages(int type, struct device *device, size_t size,
 			struct snd_dma_buffer *dmab)
@@ -229,9 +229,9 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
  * buffer type.  When no space is left, this function reduces the size and
  * tries to allocate again.  The size actually allocated is stored in
  * res_size argument.
- * 
- * Returns zero if the buffer with the given size is allocated successfully,
- * other a negative value at error.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
  */
 int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
 				 struct snd_dma_buffer *dmab)
@@ -292,7 +292,7 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab)
  * Looks for the reserved-buffer list and re-uses if the same buffer
  * is found in the list.  When the buffer is found, it's removed from the free list.
  *
- * Returns the size of buffer if the buffer is found, or zero if not found.
+ * Return: The size of buffer if the buffer is found, or zero if not found.
  */
 size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
 {
@@ -326,8 +326,8 @@ size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
  * @id: the buffer id
  *
  * Reserves the given buffer as a reserved buffer.
- * 
- * Returns zero if successful, or a negative code at error.
+ *
+ * Return: Zero if successful, or a negative code on error.
  */
 int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
 {
diff --git a/sound/core/memory.c b/sound/core/memory.c
index 66a278d0b04..36c0f1a2e18 100644
--- a/sound/core/memory.c
+++ b/sound/core/memory.c
@@ -33,7 +33,7 @@
  *
  * Copies the data from mmio-space to user-space.
  *
- * Returns zero if successful, or non-zero on failure.
+ * Return: Zero if successful, or non-zero on failure.
  */
 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
 {
@@ -66,7 +66,7 @@ EXPORT_SYMBOL(copy_to_user_fromio);
  *
  * Copies the data from user-space to mmio-space.
  *
- * Returns zero if successful, or non-zero on failure.
+ * Return: Zero if successful, or non-zero on failure.
  */
 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
 {
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 61798f85d03..578327e2bc2 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -637,7 +637,7 @@ static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substrea
  * calling this, i.e. zero must be given to the argument of
  * snd_pcm_new().
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 {
@@ -759,7 +759,7 @@ static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
  * The pcm operators have to be set afterwards to the new instance
  * via snd_pcm_set_ops().
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 		int playback_count, int capture_count, struct snd_pcm **rpcm)
@@ -787,7 +787,7 @@ EXPORT_SYMBOL(snd_pcm_new);
  * The pcm operators have to be set afterwards to the new instance
  * via snd_pcm_set_ops().
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 	int playback_count, int capture_count,
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index c4840ff75d0..41b3dfe6869 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -666,7 +666,8 @@ static inline unsigned int muldiv32(unsigned int a, unsigned int b,
  * The interval is changed to the range satisfying both intervals.
  * The interval status (min, max, integer, etc.) are evaluated.
  *
- * Returns non-zero if the value is changed, zero if not changed.
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 {
@@ -865,7 +866,8 @@ void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
  * @nump: pointer to store the resultant numerator
  * @denp: pointer to store the resultant denominator
  *
- * Returns non-zero if the value is changed, zero if not changed.
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 int snd_interval_ratnum(struct snd_interval *i,
 			unsigned int rats_count, struct snd_ratnum *rats,
@@ -983,7 +985,8 @@ EXPORT_SYMBOL(snd_interval_ratnum);
  * @nump: pointer to store the resultant numerator
  * @denp: pointer to store the resultant denominator
  *
- * Returns non-zero if the value is changed, zero if not changed.
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 static int snd_interval_ratden(struct snd_interval *i,
 			       unsigned int rats_count, struct snd_ratden *rats,
@@ -1082,7 +1085,8 @@ static int snd_interval_ratden(struct snd_interval *i,
  * When mask is non-zero, only the elements corresponding to bit 1 are
  * evaluated.
  *
- * Returns non-zero if the value is changed, zero if not changed.
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 int snd_interval_list(struct snd_interval *i, unsigned int count,
 		      const unsigned int *list, unsigned int mask)
@@ -1142,7 +1146,7 @@ static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned
  * @private: the private data pointer passed to function
  * @dep: the dependent variables
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
 			int var,
@@ -1200,6 +1204,8 @@ EXPORT_SYMBOL(snd_pcm_hw_rule_add);
  * @mask: the bitmap mask
  *
  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
 			       u_int32_t mask)
@@ -1220,6 +1226,8 @@ int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param
  * @mask: the 64bit bitmap mask
  *
  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
 				 u_int64_t mask)
@@ -1240,6 +1248,9 @@ int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_par
  * @var: hw_params variable to apply the integer constraint
  *
  * Apply the constraint of integer to an interval parameter.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
 {
@@ -1257,6 +1268,9 @@ EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
  * @max: the maximal value
  * 
  * Apply the min/max range constraint to an interval parameter.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
  */
 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
 				 unsigned int min, unsigned int max)
@@ -1288,6 +1302,8 @@ static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
  * @l: list
  * 
  * Apply the list of constraints to an interval parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
 			       unsigned int cond,
@@ -1322,6 +1338,8 @@ static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
  * @cond: condition bits
  * @var: hw_params variable to apply the ratnums constraint
  * @r: struct snd_ratnums constriants
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
 				  unsigned int cond,
@@ -1355,6 +1373,8 @@ static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
  * @cond: condition bits
  * @var: hw_params variable to apply the ratdens constraint
  * @r: struct snd_ratdens constriants
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, 
 				  unsigned int cond,
@@ -1386,6 +1406,8 @@ static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
  * @cond: condition bits
  * @width: sample bits width
  * @msbits: msbits width
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, 
 				 unsigned int cond,
@@ -1414,6 +1436,8 @@ static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
  * @cond: condition bits
  * @var: hw_params variable to apply the step constraint
  * @step: step size
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
 			       unsigned int cond,
@@ -1444,6 +1468,8 @@ static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm
  * @runtime: PCM runtime instance
  * @cond: condition bits
  * @var: hw_params variable to apply the power-of-2 constraint
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
 			       unsigned int cond,
@@ -1470,6 +1496,8 @@ static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
  * @runtime: PCM runtime instance
  * @base_rate: the rate at which the hardware does not resample
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
 			       unsigned int base_rate)
@@ -1519,8 +1547,8 @@ EXPORT_SYMBOL(_snd_pcm_hw_params_any);
  * @var: parameter to retrieve
  * @dir: pointer to the direction (-1,0,1) or %NULL
  *
- * Return the value for field @var if it's fixed in configuration space
- * defined by @params. Return -%EINVAL otherwise.
+ * Return: The value for field @var if it's fixed in configuration space
+ * defined by @params. -%EINVAL otherwise.
  */
 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
 			   snd_pcm_hw_param_t var, int *dir)
@@ -1591,7 +1619,8 @@ static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
  *
  * Inside configuration space defined by @params remove from @var all
  * values > minimum. Reduce configuration space accordingly.
- * Return the minimum.
+ *
+ * Return: The minimum, or a negative error code on failure.
  */
 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, 
 			   struct snd_pcm_hw_params *params, 
@@ -1637,7 +1666,8 @@ static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
  *
  * Inside configuration space defined by @params remove from @var all
  * values < maximum. Reduce configuration space accordingly.
- * Return the maximum.
+ *
+ * Return: The maximum, or a negative error code on failure.
  */
 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, 
 			  struct snd_pcm_hw_params *params,
@@ -1665,6 +1695,8 @@ EXPORT_SYMBOL(snd_pcm_hw_param_last);
  * The configuration chosen is that obtained fixing in this order:
  * first access, first format, first subformat, min channels,
  * min rate, min period time, max buffer size, min tick time
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
 			     struct snd_pcm_hw_params *params)
@@ -1771,7 +1803,7 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
  * Processes the generic ioctl commands for PCM.
  * Can be passed as the ioctl callback for PCM ops.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
 		      unsigned int cmd, void *arg)
@@ -2510,7 +2542,7 @@ static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
  *
  * Create channel-mapping control elements assigned to the given PCM stream(s).
- * Returns zero if succeed, or a negative error value.
+ * Return: Zero if successful, or a negative error value.
  */
 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
 			   const struct snd_pcm_chmap_elem *chmap,
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index 69e01c4fc32..0af622c34e1 100644
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -95,7 +95,7 @@ static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream
  *
  * Releases the pre-allocated buffer of the given substream.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
 {
@@ -115,7 +115,7 @@ int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
  *
  * Releases all the pre-allocated buffers on the given pcm.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 {
@@ -265,7 +265,7 @@ static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
  * destruction time.  The dma_buf_id must be unique for all systems
  * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 				  int type, struct device *data,
@@ -289,7 +289,7 @@ EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
  * Do pre-allocation to all substreams of the given pcm for the
  * specified DMA type.
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 					  int type, void *data,
@@ -313,8 +313,9 @@ EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
  * @substream: the pcm substream instance
  * @offset: the buffer offset
  *
- * Returns the page struct at the given buffer offset.
  * Used as the page callback of PCM ops.
+ *
+ * Return: The page struct at the given buffer offset. %NULL on failure.
  */
 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 {
@@ -337,7 +338,7 @@ EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
  * Allocates the DMA buffer on the BUS type given earlier to
  * snd_pcm_lib_preallocate_xxx_pages().
  *
- * Returns 1 if the buffer is changed, 0 if not changed, or a negative
+ * Return: 1 if the buffer is changed, 0 if not changed, or a negative
  * code on failure.
  */
 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
@@ -390,7 +391,7 @@ EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
  *
  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
  *
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 {
@@ -437,6 +438,8 @@ EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
  * @substream: the substream with a buffer allocated by
  *	snd_pcm_lib_alloc_vmalloc_buffer()
+ *
+ * Return: Zero if successful, or a negative error code on failure.
  */
 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 {
@@ -458,6 +461,8 @@ EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
  * @offset: offset in the buffer
  *
  * This function is to be used as the page callback in the PCM ops.
+ *
+ * Return: The page struct, or %NULL on failure.</