On Tue, May 12, 2015 at 07:08:13PM -0700, Ben Zhang wrote:

I have a question about the design of ASoC suspend/resume path. Who should call snd_soc_suspend() and snd_soc_resume()?

They are part of the soc-audio driver's dev_pm_ops, but some ASoC platform drivers also calls them. For example,

hsw_pcm_prepare() in sound/soc/intel/haswell/sst-haswell-pcm.c sst_soc_prepare() in sound/soc/intel/atom/sst-mfld-platform-pcm.c

The machine driver needs to ensure that they are called. If it has nothing specific it needs to do it can just provide them as ops directly, or it can call them from within its own suspend and resume calls. No new systems should be using the soc-audio device.