diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index 1064044c..b53797a6 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -820,6 +820,7 @@ int snd_pcm_nonblock(snd_pcm_t *pcm, int nonblock)
  * \param sig Signal to raise: < 0 disable, 0 default (SIGIO)
  * \param pid Process ID to signal: 0 current
  * \return 0 on success otherwise a negative error code
+ * \return -ENOSYS Async is not supported on this PCM
  *
  * A signal is raised every period.
  */
@@ -850,6 +851,7 @@ int snd_pcm_async(snd_pcm_t *pcm, int sig, pid_t pid)
  * \param pcm PCM handle
  * \param info Information container
  * \return 0 on success otherwise a negative error code
+ * \return -ENOSYS Info is not supported on this PCM
  */
 int snd_pcm_info(snd_pcm_t *pcm, snd_pcm_info_t *info)
 {
@@ -867,6 +869,7 @@ int snd_pcm_info(snd_pcm_t *pcm, snd_pcm_info_t *info)
  * \param pcm PCM handle
  * \param params Configuration space definition container
  * \return 0 on success otherwise a negative error code
+ * \return -EBADFD PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
  */
 int snd_pcm_hw_params_current(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
 {
@@ -933,6 +936,7 @@ int snd_pcm_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
 /** \brief Remove PCM hardware configuration and free associated resources
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \return -ENOSYS Hw_free is not supported on this PCM
  */
 int snd_pcm_hw_free(snd_pcm_t *pcm)
 {
@@ -960,7 +964,9 @@ int snd_pcm_hw_free(snd_pcm_t *pcm)
  * \param pcm PCM handle
  * \param params Configuration container
  * \return 0 on success otherwise a negative error code
- *
+ * \retval -EIO PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EINVAL Incorrect parameter, avail_min cannot be 0
+ * 
  * The software parameters can be changed at any time.
  * The hardware parameters cannot be changed when the stream is
  * running (active).
@@ -1017,6 +1023,7 @@ int snd_pcm_sw_params(snd_pcm_t *pcm, snd_pcm_sw_params_t *params)
  * \param pcm PCM handle
  * \param status Status container
  * \return 0 on success otherwise a negative error code
+ * \return -ENOSYS Status is not supported on this PCM
  *
  * The function is thread-safe when built with the proper option.
  */
@@ -1060,7 +1067,8 @@ snd_pcm_state_t snd_pcm_state(snd_pcm_t *pcm)
  * \brief (DEPRECATED) Synchronize stream position with hardware
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
- *
+ * \retval -EIO PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * 
  * Note this function does not update the actual r/w pointer
  * for applications. The function #snd_pcm_avail_update()
  * have to be called before any mmap begin+commit operation.
@@ -1089,6 +1097,7 @@ int snd_pcm_hwsync(snd_pcm_t *pcm)
  * \param pcm PCM handle
  * \param delayp Returned delay in frames
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
  *
  * For playback the delay is defined as the time that a frame that is written
  * to the PCM stream shortly after this call will take to be actually
@@ -1133,6 +1142,7 @@ int snd_pcm_delay(snd_pcm_t *pcm, snd_pcm_sframes_t *delayp)
  * \brief Resume from suspend, no samples are lost
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
  * \retval -EAGAIN resume can't be proceed immediately (audio hardware is probably still suspended)
  * \retval -ENOSYS hardware doesn't support this feature
  *
@@ -1166,6 +1176,8 @@ int snd_pcm_resume(snd_pcm_t *pcm)
  * \param avail Number of available frames when timestamp was grabbed
  * \param tstamp Hi-res timestamp
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -ENOSYS Hi-res timestamp is not supported on this system.
  *
  * Note this function does not update the actual r/w pointer
  * for applications.
@@ -1194,6 +1206,9 @@ int snd_pcm_htimestamp(snd_pcm_t *pcm, snd_pcm_uframes_t *avail, snd_htimestamp_
  * \brief Prepare PCM for use
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -ENOSYS Prepare is not supported on this PCM
+ * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_DISCONNECTED)
  *
  * The function is thread-safe when built with the proper option.
  */
@@ -1222,6 +1237,8 @@ int snd_pcm_prepare(snd_pcm_t *pcm)
  * \brief Reset PCM position
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -ENOSYS Reset is not supported on this PCM
  *
  * Reduce PCM delay to 0.
  *
@@ -1249,6 +1266,8 @@ int snd_pcm_reset(snd_pcm_t *pcm)
  * \brief Start a PCM
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED)
  *
  * The function is thread-safe when built with the proper option.
  */
@@ -1274,6 +1293,8 @@ int snd_pcm_start(snd_pcm_t *pcm)
  * \brief Stop a PCM dropping pending frames
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED,DRAINING,SETUP or SUSPENDED)
  *
  * This function stops the PCM <i>immediately</i>.
  * The pending samples on the buffer are ignored.
@@ -1309,7 +1330,10 @@ int snd_pcm_drop(snd_pcm_t *pcm)
  * \brief Stop a PCM preserving pending frames
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING,SETUP or SUSPENDED)
  * \retval -ESTRPIPE a suspend event occurred
+ * \retval -ENOSYS Drain is not supported on this PCM
  *
  * For playback wait for all pending frames to be played and then stop
  * the PCM.
@@ -1345,6 +1369,10 @@ int snd_pcm_drain(snd_pcm_t *pcm)
  * \param pcm PCM handle
  * \param enable 0 = resume, 1 = pause
  * \return 0 on success otherwise a negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING)
+ * \retval -ESTRPIPE a suspend event occurred
+ * \retval -ENOSYS Pause is not supported on this PCM
  *
  * Note that this function works only on the hardware which supports
  * pause feature.  You can check it via \link ::snd_pcm_hw_params_can_pause() \endlink
@@ -1377,6 +1405,10 @@ int snd_pcm_pause(snd_pcm_t *pcm, int enable)
  * \brief Get safe count of frames which can be rewinded
  * \param pcm PCM handle
  * \return a positive number of frames or negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING)
+ * \retval -ESTRPIPE a suspend event occurred
+ * \retval -ENOSYS Rewindable is not supported on this PCM
  *
  * Note: The snd_pcm_rewind() can accept bigger value than returned
  * by this function. But it is not guaranteed that output stream
@@ -1412,6 +1444,9 @@ snd_pcm_sframes_t snd_pcm_rewindable(snd_pcm_t *pcm)
  * \param frames wanted displacement in frames
  * \return a positive number for actual displacement otherwise a
  * negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING)
+ * \retval -ENOSYS Rewind is not supported on this PCM
  *
  * The function is thread-safe when built with the proper option.
  */
@@ -1443,6 +1478,9 @@ snd_pcm_sframes_t snd_pcm_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
  * \brief Get safe count of frames which can be forwarded
  * \param pcm PCM handle
  * \return a positive number of frames or negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING)
+ * \retval -ENOSYS Forwardable is not supported on this PCM
  *
  * Note: The snd_pcm_forward() can accept bigger value than returned
  * by this function. But it is not guaranteed that output stream
@@ -1478,6 +1516,9 @@ snd_pcm_sframes_t snd_pcm_forwardable(snd_pcm_t *pcm)
  * \param frames wanted skip in frames
  * \return a positive number for actual skip otherwise a negative error code
  * \retval 0 means no action
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EBADFD PCM is not in the right state (Should be PREPARED,RUNNING,XRUN,PAUSED or DRAINING)
+ * \retval -ENOSYS Forward is not supported on this PCM
  *
  * The function is thread-safe when built with the proper option.
  */
@@ -1517,6 +1558,8 @@ use_default_symbol_version(__snd_pcm_forward, snd_pcm_forward, ALSA_0.9.0rc8);
  * \param size frames to be written
  * \return a positive number of frames actually written otherwise a
  * negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EINVAL Access type is not Interleave type.
  * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
  * \retval -EPIPE an underrun occurred
  * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
@@ -1556,6 +1599,8 @@ snd_pcm_sframes_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_ufr
  * \param size frames to be written
  * \return a positive number of frames actually written otherwise a
  * negative error code
+ * \retval -EIO    PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EINVAL Access type is not Non-Interleave type.
  * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
  * \retval -EPIPE an underrun occurred
  * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
@@ -1595,6 +1640,8 @@ snd_pcm_sframes_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t
  * \param size frames to be read
  * \return a positive number of frames actually read otherwise a
  * negative error code
+ * \retval -EIO PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EINVAL Access type is not Interleave type.
  * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
  * \retval -EPIPE an overrun occurred
  * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
@@ -1634,6 +1681,8 @@ snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t
  * \param size frames to be read
  * \return a positive number of frames actually read otherwise a
  * negative error code
+ * \retval -EIO PCM has not been setup (PCM isn't configured yet, or lifecycle of PCM has been ended)
+ * \retval -EINVAL Access type is not Non-Interleave type.
  * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
  * \retval -EPIPE an overrun occurred
  * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
@@ -1669,8 +1718,9 @@ snd_pcm_sframes_t snd_pcm_readn(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t s
 /**
  * \brief Link two PCMs
  * \param pcm1 first PCM handle
- * \param pcm2 first PCM handle
+ * \param pcm2 second PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -ENOSYS Link is not supported on pcm1
  *
  * The two PCMs will start/stop/prepare in sync.
  */ 
@@ -1691,6 +1741,7 @@ int snd_pcm_link(snd_pcm_t *pcm1, snd_pcm_t *pcm2)
  * \brief Remove a PCM from a linked group
  * \param pcm PCM handle
  * \return 0 on success otherwise a negative error code
+ * \retval -ENOSYS Unlink is not supported on this PCM.
  */
 int snd_pcm_unlink(snd_pcm_t *pcm)
 {
