[PATCH] ASoC: fsl_esai: Add spin lock to protect reset and stop

[S.j. Wang]

Hi
> 
> On Wed, Oct 23, 2019 at 03:29:49PM +0800, Shengjiu Wang wrote:
> > xrun may happen at the end of stream, the
> > trigger->fsl_esai_trigger_stop maybe called in the middle of
> > fsl_esai_hw_reset, this may cause esai in wrong state after stop, and
> > there may be endless xrun interrupt.
> 
> What about fsl_esai_trigger_start? It touches ESAI_xFCR_xFEN bit that is
> being checked in the beginning of fsl_esai_hw_reset.
> 
> Could the scenario below be possible also?
> 
> 1) ESAI TX starts
> 2) Xrun happens to TX
> 3) Starting fsl_esai_hw_reset (enabled[TX] = true; enabled[RX] = false)
> 4) ESAI RX starts
> 5) Finishing fsl_esai_hw_reset (enabled[RX] is still false)
> 
> 
Good catch, this may possible.  Will update in v2.

Best regards
Wang shengjiu