Re: [alsa-devel] [PATCH] ALSA: pcm_lib: avoid timing jitter in snd_pcm_read/write()

2010/6/28 David Dillow dave@thedillows.org

Perhaps documentation that recommends setting avail_min to 1 when using read/write to avoid this issue would be helpful, in lieu of changing the ALSA code or giving concrete guarantees.

Dave

Refer to http://article.gmane.org/gmane.linux.alsa.devel/69333/match=avail_min

avail_min cannot be less than period size , however set_avail_min() did not return any error when the value is less than period size and this mislead the programmers to believe that they can set avail_min to 1

if you want low latency, you need to use small period size