At Thu, 27 Nov 2014 14:42:00 +0800, Raymond Yau wrote: > > > > > > > For those creative sound cards (e.g. emu10k1, ca0106) which use multi > > > plugin for surround playback > > > > > > It seem that set start_threshold to -1 has no effect on some devices > (e.g. > > > multi plugin) , the device seem automatically started and pulseaudio > does > > > not check pcm state when calling snd_pcm_start > > > > > > (alsa-lib)pcm_hw.c: SNDRV_PCM_IOCTL_START failed (-77) > > > > > > Does it mean bug of multi plugin or start_threshold.have no effect on > some > > > devices/plugin ? > > > > I'm not sure whether the value -1 is valid for start_threshold at > > all. Usually it's set between 1 and boundary. > > > > > If zero is not valid stop threshold, I suggest to return error when > application set start threshold to zero If the expected behavior is not to start stream automatically, try to change -1 with the value obtained from snd_pcm_sw_params_get_boundary() (after calling snd_pcm_sw_params_current()). Does it work better? Takashi
