[alsa-devel] [PATCH] ASoC: sun4i-i2s: don't try to start up or shut down DAI if it's active

[Vasily Khoruzhick]

On Monday, October 15, 2018 1:11:51 AM PDT Maxime Ripard wrote:
> On Fri, Oct 12, 2018 at 09:28:56AM -0700, Vasily Khoruzhick wrote:
> > On Friday, October 12, 2018 9:09:05 AM PDT Mark Brown wrote:
> > > On Fri, Oct 12, 2018 at 08:32:54AM -0700, Vasily Khoruzhick wrote:
> > > > Otherwise we may end up with shutting down I2S if shutdown() was
> > > > called for capture substream, but playback is still running.
> > > 
> > > Would it be cleaner and more robust to use runtime PM?  I'm wondering
> > > what happens if some of the configuration stuff turns out to also need
> > > some of the clocks for example.
> > 
> > I guess. I'm not sure why this code was put into startup and shutdown
> > callbacks in first place.
> > 
> > Maybe Marcus or Maxime know?
> 
> I can't really come up with a good explanation, so I guess there's
> none :)
> 
> > As for configuration - only bus clock is necessary for configuration
> > and it's already enabled in runtime_resume() callback.
> 
> Not really. Or at least, on the A64, yes, but shutting down the bus
> clock on older SoCs will reset the controller. I'd just put the enable
> bit on the runtime_pm hook.

OK, will do.

> Maxime