[PATCH v2 2/2] ASoC: fsl_sai: Refine enable and disable sequence for synchronous mode

[Nicolin Chen]

On Wed, Aug 05, 2020 at 10:23:53AM +0800, Shengjiu Wang wrote:
> Tx synchronous with Rx:
> The TCSR.TE is no need to enabled when only Rx is going to be enabled.
> Check if need to disable RSCR.RE before disabling TCSR.TE.
> 
> Rx synchronous with Tx:
> The RCSR.RE is no need to enabled when only Tx is going to be enabled.
> Check if need to disable TSCR.RE before disabling RCSR.TE.

Please add to the commit log more context such as what we have
discussed: what's the problem of the current driver, and why we
_have_to_ apply this change though it's sightly against what RM
recommends.

(If thing is straightforward, it's okay to make the text short.
 Yet I believe that this change deserves more than these lines.)

One info that you should mention -- also the main reason why I'm
convinced to add this change: trigger() is still in the shape of
the early version where we only supported one operation mode --
Tx synchronous with Rx. So we need an update for other modes.

> Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>

The git-diff part looks good, please add this in next ver.:

Reviewed-by: Nicolin Chen <nicoleotsuka at gmail.com>

Btw, the new fsl_sai_dir_is_synced() can be probably applied to
other places with a followup patch.