[alsa-devel] [v4 10/12] ASoC: Intel: mrfld: add the DSP DAPM widgets

[Subhransu S. Prusty]

On Mon, Aug 18, 2014 at 08:56:33AM -0500, Mark Brown wrote:
> On Mon, Aug 18, 2014 at 09:58:11AM +0530, Subhransu S. Prusty wrote:
> > On Thu, Aug 14, 2014 at 02:07:08PM +0100, Mark Brown wrote:
> 
> > > > for (i = 0; i < w->num_kcontrols; i++) {
> > > > 	if (dapm_kcontrol_get_value(w->kcontrols[i])) {
> > > > 		val |= 1 << i;
> > > > }
> 
> > > > Is this ok?
> 
> > > No, that doesn't seem safe.  Why not read the data from the control - if
> > > we were calling a function which returned the value that'd be much
> > > clearer.
> 
> > So lets step back and see what is required here.
> 
> > I get a mixer update for one of the inputs of the mixer. This needs to be
> > communicated to the DSP via the IPC. But the IPC expects that we send all
> > the values of all the inputs of a mixer to the DSP.
> 
> > That is why here we are reading the all mixer inputs to find the values and
> > send the bitmap of all inputs.
> 
> > So from the driver if I have to find out what is the value of the inputs in
> > mixer, how do I do that, is there a simpler way? Or should we push
> > this/<something else> into framework to query
> 
> The problem is that it looks like you are reading the value from the
> control, treating it as a boolean and discarding it.
Well the mixer input is on/off, so it should be treated as boolean. How will
it have any other value.

Btw I am thinking to create an API dapm_kcontrol_get_mixer_values() which can
give me bit map of all the mixer inputs, so I can use it and send IPCs to
the DSP.




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