[alsa-devel] ASoC: sgtl5000: recording issue at 8 kHz with fsl-imx28

[Fischer, Christian]

It's me again.

I just found out that the audio playback is affected by this problem too.
Maybe this can serve as a hint.

Regards,
Christian

-----Ursprüngliche Nachricht-----
Von: alsa-devel-bounces at alsa-project.org [mailto:alsa-devel-bounces at alsa-project.org] Im Auftrag von Fischer, Christian
Gesendet: Mittwoch, 10. Januar 2018 11:31
An: alsa-devel at alsa-project.org
Cc: 'Takashi Iwai' <tiwai at suse.com>; 'Mark Brown' <broonie at kernel.org>; 'Liam Girdwood' <lgirdwood at gmail.com>
Betreff: [alsa-devel] ASoC: sgtl5000: recording issue at 8 kHz with fsl-imx28

Hello guys,

trying to record from a SGTL5000 with 8 kHz sampling rate gives a very bad audio quality.
All other sampling rates working fine.

Initially posted at NXP forum: https://community.nxp.com/message/975131

Tested with imx28, sgtl5000 and Kernel 4.14.12.

I've attached a recording with 8 kHz, capture-vol was 67, mic-gain 33, AVC-off and Capture-ZC off.
Recorded with "arecord -D "hw:0,1" -t wav -f S16_LE -c 2 -r 8000 test.wav".
Sounds like there are missing samples..

The microphone is powered from mic-bias and decoupled with a 100nF capacitor.

Can anybody help me?
Thank you guys!
Kind regards,

Christian Fischer