[alsa-devel] [RFD] Add hw_params support for hostless stream BE DAIs

[Mark Brown]

On Tue, Feb 16, 2016 at 09:47:47PM +0530, Jeeja KP wrote:
> We have no mechanism to configure hw_params for DAIs which are hostless.
> Like a loop or DAIs connected to internal sinks/sources.

Please propose patches, don't send enormous design documents.  They're
big, take a long time to read and don't really get us anywhere unless
they're extremely clear.

> Approach:
> 	1. Allow params to be defined for other BE dai link also. this
> 	currently applicable only for codec_codec link.

Like I keep saying if you're thinking about this in terms of DPCM you're
solving the wrong problem - we already support supplying parameters for
device<->device links, we already have systems that need to configure
things for device<->device links so we can already see that if we're
doing something that only works for things that are on SoC and can use
DPCM then we're not solving the problem.

DPCM works pretty well for small, simple DSPs that are mostly in line
in the middle of a standard DAI but it does have limitations which
you're now running into.  Your systems don't fit well with what DPCM
supports naturally.

> struct snd_soc_dai_link {
>         const struct snd_soc_pcm_stream *params;
>         unsigned int num_params;
> 
> +       /* flag to create codec codec based on the flag*/
> +       unsigned int codec_link:1;
> +

This is clearly confused, if we can't figure out what the two devices we
are connecting are based on just looking at the devices then that's
really not a good sign that our interfaces are sensible and easy to work
with.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: not available
URL: <http://mailman.alsa-project.org/pipermail/alsa-devel/attachments/20160302/e2fb06e7/attachment.sig>