On Mon, Feb 06, 2017 at 07:37:03AM +1100, Matt Flax wrote:
> On 06/02/17 03:34, Mark Brown wrote:

> > Looking at the driver it may be possible for the hardware to do DSP
> > modes at which point this gets much easier but right now it only has I2S
> > support, I've got a feeling that the other end of the link may actually
> > be running in a DSP mode.

> You've got it !

If you're actually using the device in DSP mode you need to be showing
that in the driver, not claiming that it's I2S.

> I haven't looked into why, but I am getting the correct channel mapping
> under the hood. To me that is a concern of the higher up levels of the ALSA
> driver - it was a pleasant surprise when it worked nicely, because to me it
> indicated a robustly coded system.

If the external device is running in DSP mode it'll work fine.

> My next patch is to allow DSP modes in this I2S driver. I wanted to make
> sure that this got through first however.

This is the wrong way round.

> The majority of these other concerns you mention are controlled at the
> machine driver level.

The driver should be checking for errors, it shouldn't be silently
accepting incorrect configurations - we shouldn't be forcing all the
machine drivers to replicate code for this, or requiring modifications
to machine drivers because a new feature has been added to one of the
drivers it uses.