[alsa-devel] Rate or plug plugin issue with snd-pcsp

[Raymond Yau]

>
> While testing application support for weird-rate cards (such as
snd-pcsp), I found a bug in alsa-lib. Alsa-plugins are installed, so the
"libspeex (builtin)" rate converter is used. This bug already exists in
alsa-plugins 1.0.27.2, so not a regression and thus should not block 1.0.28.
>
> $ file test.wav
> test.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit,
stereo 32000 Hz
>
> $ aplay -vvv -D plughw:pcsp test.wav
> Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 32000 Hz,
Stereo
> aplay: set_params:1297: Unable to install hw params:
> ACCESS:  RW_INTERLEAVED
> FORMAT:  S16_LE
> SUBFORMAT:  STD
> SAMPLE_BITS: 16
> FRAME_BITS: 32
> CHANNELS: 2
> RATE: NONE
> PERIOD_TIME: (125006 125007)
> PERIOD_SIZE: NONE
> PERIOD_BYTES: (16000 16004)
> PERIODS: (3 4)
> BUFFER_TIME: 500000
> BUFFER_SIZE: 16000
> BUFFER_BYTES: 64000
> TICK_TIME: 0
>
> The pcsp device supports the sample rate of 37286 Hz.

PERIOD_SIZE: NONE

Seem driver bug which use sndrv_pcm_rate_knot when only support single rate
and

The constraint refinement  need driver  usIng equal size periods

snd_pcm_hw_constraint_integer(runtime,
   SNDRV_PCM_HW_PARAM_PERIODS)