[alsa-devel] Can DAPM paths span multiple codecs/drivers?

[Mike Looijmans]

If two codecs need each other for certain operations, is there a way to 
define DAPM links between them?

For example, codec A has an analog input "x". It can route this input 
via some output pin to an input of codec B. (In other words, A could be 
a codec that provides an SPDIF output and B could be a codec that can 
only handle digital inputs like the SPDIF from codec A).

Now codec B can record from input "x", but to do so, it would have to 
activate a path leading through codec A. (hence, codec A will need to be 
a bit active)

I have a suspicion that this is possible by hand-crafting some of the 
dapm structs and linking them together. Before I try, I would like to 
know if there's even a possiblity that this will work from folks more 
knowledgable on this topic.

My current implementation is to tell DAPM that i have an "always 
enabled" ADC path and just do everything myself. Which is of course 
wasteful.

Mike.