Audio troubleshooting grid

Revision as of 14:36, 24 October 2022 by Registered User
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Applicable for STM32MP13x lines, STM32MP15x lines

Some typical issues related to the audio domain are listed below. Solutions or debugging methods are proposed for these issues.

If your issue is not listed, try looking at in the articles in the Audio or troubleshooting grids categories.


Symptom Resolution
ALSA
The sound card does not probe. If one or more audio interfaces are missing, the sound card cannot probe:
- Look for missing audio interfaces in /sys/kernel/debug/asoc/dais.
- Check kernel config, modules and error trace for missing interfaces.
aplay: pcm_write:2030:
write error: Input/output error

This error occurs on an audio playback, when audio samples are not output. A possible cause is a wrong configuration of the audio interface:

- DAI gpios not activated: missing in DT or in bad state
- DAI/codec not clocked: kernel/master clock not enabled

Refer to Soundcard configuration

Error -16 setting sai_ck parent clock.
Active stream rates conflict

The two SAI sub blocks which are connected to the audio codec, share their master clock on Disco and Evaluation boards. When running both capture and playback on the codec, the chosen sampling rates must be multiple of each other, because of this dependency. If sampling rates are not compatible, an error is issued.


Miscellaneous
Silence is recorded from headset microphone. The following points have to be checked:
- The headset jack must be compatible with CTIA standard.
- Check volumes and mute switches in record path. (ALSA control configuration and Pulseaudio settings)
- Check that the codec is fed with master clock.
The capture level is too low at maximum volume. The ALSA plugin softvol [1] can be used to boost the volume. However, this may lead to saturation.

References[edit]