Mark Brown wrote:
I don't think this is a bug in the core, relying on the having things partially initialised in a particular order seems overly fragile - better to check for the thing you're actually looking for. There wasn't a deliberate change I can think of here, though.
I think it's because you test the codec_dai in soc_new_pcm(), which seems weird. I put some printks in this function, and this is what I got:
soc_new_pcm:2132 codec_dai=e6998840 soc_new_pcm:2133 codec_dai->driver->playback.channels_min=2 soc_new_pcm:2134 codec_dai->driver->capture.channels_min=0 soc_new_pcm:2136 cpu_dai->driver->playback.channels_min=2 soc_new_pcm:2137 cpu_dai->driver->capture.channels_min=2 soc_new_pcm:2144 playback=1 soc_new_pcm:2145 capture=0 soc_new_pcm:2173 platform->driver->pcm_new=c0329fd0 soc_new_pcm:2176 fsl_dma_new:305 dai->driver->playback.channels_min=2 fsl_dma_new:306 dai->driver->capture.channels_min=2 fsl_dma_new:329 pcm=e69aae00 fsl_dma_new:330 pcm->streams[1].substream= (null)
It just so happens that on the the P1022, the CPU does support both directions in its DAI, but the codec (WM8776) supports only one direction per DAI. So I suspect that you shouldn't be testing codec_dai either, because it assumes that the codec is the only arbiter on which direction a given dai-group supports.
Anyway, I changed my driver to test for the actual pointer, and it works. You might want to consider doing the same in soc_pcm_new().