Re: [RFC/RFT PATCH] Revert "ASoC: fsl_esai: ETDR and TX0~5 registers are non volatile"

On Thu, Jun 06, 2019 at 04:01:05PM -0700, Nicolin Chen wrote:

This reverts commit 8973112aa41b8ad956a5b47f2fe17bc2a5cf2645.

Please use subject lines matching the style for the subsystem.  This
makes it easier for people to identify relevant patches.

1) Though ETDR and TX0~5 are not volatile but write-only registers,
   they should not be cached either. According to the definition of
   "volatile_reg", one should be put in the volatile list if it can
   not be cached.

There's no problem with caching write only registers, having a cache
allows one to do read/modify/write cycles on them and can help with
debugging.  The original reason we had cache code in ASoC was for write
only devices.