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

[Fabio Estevam]

On Thu, Nov 13, 2014 at 4:34 AM, Craig McQueen
<craig.mcqueen at beamcommunications.com> wrote:
> I'm testing the 3.18 kernel for i.MX28 EVK, which has an SGTL5000 CODEC. I
> notice that audio cannot be output at 8 kHz or 11.025 kHz, although the
> SGTL5000 data sheet table 8 indicates this should be possible.
>
> If I try to play or record at 8 kHz or 11.025 kHz, I get an error message:
>
>     # aplay test_8k.wav
>     [ 6168.910201] mxs_evk_startup: Skipped programming wolfson codec

Is this really a mainline kernel? I don't see any 'mxs_evk_startup' in mainline.

>     Playing WAVE 'test_8k.wav' : Signed 16 bit Little Endian, Rate 8000 Hz,
> Mono
>     [ 6168.941211] sgtl5000 0-000a: Invalid mclk frequency: 4.096MHz
>     [ 6168.947047] mxs-sgtl5000 sound.11: ASoC: machine hw_params failed:
> -22
>     aplay: set_params:1145: Unable to install hw params:
>     ...
>
> For an 8 kHz sample rate, I get
>
>     Invalid mclk frequency: 4.096MHz

I am not able to reproduce this bug here. I can play 8kHz file on the mx28evk:

root at freescale /home$ aplay mono_8k.wav
Playing WAVE 'mono_8k.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono