On Tue, Sep 03, 2013 at 12:00:11AM +0100, Russell King - ARM Linux wrote:
You should have one back end DAI per physical DAI.
What do you mean "physical DAI"? Do you mean "CPU DAI" which would be a front end DAI?
The same question got asked and answered in another subthread but for the record I'm speaking here about the back end DAIs - there should be one for S/PDIF and one for I2S. With DPCM there should also be a front end DAI for the DMA. I've cut a bunch of other discussion which was duplicated in that subthread.
Unless there is a need to actually take some action you can, naturally, provide stubs. You should provide the minimal set of stubs required for operation in your testing.
That needs to go in the ASoC code though - I don't think I have access to the ALSA PCM which has been created for the backend DAI(s). Remember, the backend DAIs are "owned" by the dummy DAI driver, not the CPU driver, so the CPU driver doesn't get to see any operations for that.
If you need to define operations for the dummy driver then modify the dummy driver. However as indicated in the other thread you should not be using the dummy DAI driver for the CPU side back end.