On Wed, Jul 17, 2013 at 11:16:22AM +0200, Daniel Mack wrote:
On 16.07.2013 19:47, Mark Brown wrote:
Half the point of soc-pcm is to decouple the streams seen by the application layer from the DAIs that the driver sees so I'd expect us to be able to map a single application layer/memory stream onto multiple CODEC DAIs. One front end connected to two back ends.
You're talking about DPCM, right? Unfortunately, there is no active user of this in mainline, and no documentation either. I'll try and find out how this is supposed to work first ...
Yes, this is a constant complaint. Hopefully the OMAP4 code will be upstreamed at some point but as you will be aware there's issues there.
Maybe Liam has some explanation ready?
The only thing I'm aware of is the out of tree OMAP4 and Qualcomm code neither of which I'd hold my breath over.
May as well bite the bullet and do the refactoring, it should be automatable. There's also the fun of handling what happens when you want to stream from one CODEC to another but I think that's second stage...
Looking deeper into this, I'm not sure whether each of those codec instances inside one snd_soc_dai_link should have it own runtime, of if they should rather share one. The latter isn't straight-forward, as current users simply access the codec from their callbacks as rtd->codec_dai. However, open-coding routines to access the correct codec from these callbacks is not nice at all either. Hmm.
Yes, it's not an easy refactoring. But it's probably one that'll be needed for Slimbus at some point.