[alsa-devel] hw_ptr accuracy with intel8x0 -> PulseAudio issue

Raymond Yau superquad.vortex2 at gmail.com
Sun Dec 13 03:50:11 CET 2009

2009/12/10 pl bossart <bossart.nospam at gmail.com>

> > 2) why PA use  snd_pcm_hw_params_get_buffer_size_max() instead of
> > snd_pcm_hw_params_get_buffer_size() after snd_pcm_hw_params() ?
> Precisely to use the maximum preallocated buffer size.

D: module-alsa-sink.c: latency set to 46.44ms
D: module-alsa-sink.c: hwbuf_unused_frames=1
D: module-alsa-sink.c: setting avail_min=4662
D: module-alsa-sink.c: Requesting rewind due to latency change.
D: module-alsa-sink.c: Requested to rewind 8192 bytes.
D: module-alsa-sink.c: Limited to 3712 bytes.
D: module-alsa-sink.c: before: 928

The driver only allocated the requested buffer size at hw_param callback

As you can see , PA only rewind 8192 bytes only instead of 371 ms ?

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