[alsa-devel] Low sample rates for SGTL5000 on i.MX28

[Fabio Estevam]

On Thu, Nov 13, 2014 at 8:36 PM, Craig McQueen
<craig.mcqueen at beamcommunications.com> wrote:

> If you're playing a mono file successfully, then you must be going through
> an ALSA plugin that does some sort of rate/format/channel conversion. That
> depends on what's in asoundrc. Please try it with the -D hw:0,0 parameter
> and a stereo file.

That's interesting: I can play your three wav files if I run "aplay
file.wav" on mx28evk.

However, if I pass -D hw:0,0 I get different results:

aplay -D hw:0,0 stereo_16k.wav
Playing WAVE 'stereo_16k.wav' : Signed 16 bit Little Endian, Rate
16000 Hz, Stereo

also works, but:

root at freescale /home$  aplay -D hw:0,0 stereo_8k.wav
Playing WAVE 'stereo_8k.wav' : Signed 16[ 1023.301833] sgtl5000 0-000a: Invalid
mclk frequency: 4.096MHz
 bit Little Endian, Rate[ 1023.309341] mxs-sgtl5000 sound: ASoC: machine hw_para
ms failed: -22
 8000 Hz, Stereo
aplay: set_params:1123: Unable to install hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  S16_LE
SUBFORMAT:  STD
SAMPLE_BITS: 16
FRAME_BITS: 32
CHANNELS: 2
RATE: 8000
PERIOD_TIME: 125000
PERIOD_SIZE: 1000
PERIOD_BYTES: 4000
PERIODS: 4
BUFFER_TIME: 500000
BUFFER_SIZE: 4000
BUFFER_BYTES: 16000
TICK_TIME: 0

Not sure why 'aplay -D hw:0,0 stereo_8k.wav' works and 'aplay
stereo_8k.wav' succeeds.