Felix Lazarev

subtle bug with alsa driver backend or mxs-dac driver.

Discussion created by Felix Lazarev on Jan 25, 2012
Latest reply on Jan 27, 2012 by Felix Lazarev

I'm hunting for subtle bug, happened under certain conditions:

 -- if application is LATE to feed alsa through snd_pcm_writei, the driver spits "DAC Underflow" . 

 after several underflows, entire sound subsystem stops working. alsa snd_pcm_writei returns -EAGAIN even after relaunching application. The only remedy is reboot.

I suspect that either AUDIOOUT fifo or DMA is stuck in error condition, and there is no code to recover from it. 

Has anyone experienced this issue?

 

LTIB kernel 2.6.31. all default parameters for imx233evk

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