From: ChangJoon Lee <changjoon.lee@xxxxxxx> Hi, ALSA Teams, This is documentation update purpose patch. This patch does NOT alter any of operations. This patch allows an application engineer to understand why they received negative return such as -EIO, -EBADFD, -ENOSYS, -ESTRPIPE and etc which are not fully documented on documentation site. This patch also exposes Expected Status of PCM based on bad_pcm_state() with P_STATE to help engineer to understand API behavior to the documentation site. TODO : We may need improve consistency of return value especially for snd_pcm_hw_params_current(). It returns -EBADFD when PCM is not setup while other API returns -EIO in this case. src/pcm/pcm.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 3 deletions(-) -- 2.26.2