On Thu, Sep 05, 2019 at 12:06:23AM +0900, Katsuhiro Suzuki wrote:

> Would you tell me one more thing. I don't understand who sets MCLK to 0.
> Is it needed original machine driver instead of audio-graph-card?

> On my test environment (audio-graph-card + Rockchip I2S + ES8316), it
> seems audio-graph-card has never called set_sysclk() with freq = 0 after
> stop play/capture sound. So my env will go to bad scenario as I described in
> this patch.

You shouldn't need a custom machine driver - you'll just be the first
person who ran into this with audio-graph-card.  I'd just add this
support to the audio-graph-card, either with custom startup and shutdown
callbacks or using a set_bias_level() callback (both get used, I'd guess
the set_bias_level() is easier since you don't need to reference count
anything).