On 12/20/2013 03:25 PM, Timur Tabi wrote:
Lars-Peter Clausen wrote:
The ASoC core assumes that the PCM component of the ASoC card transparently moves data around and does not impose any restrictions on the memory layout or the transfer speed. It ignores all fields from the snd_pcm_hardware struct for the PCM driver that are related to this. Setting these fields in the PCM driver might suggest otherwise though, so rather not set them.
Is this new? There are formats that the codec and the SSI support that the DMA controller does NOT support, like packed 24-bit samples. How do we ensure that we never get those?
No, this is how it has always been. If there are restrictions imposed by the DMA controller we need to add support for expressing this inside the ASoC framework. But I think it will probably be more complex than just saying the DMA controller supports format A, B, C and the DAI controller supports format B, C, D and then just do the intersection of both. E.g. the DAI controller probably does not care whether the samples are packed or not if it only sees one sample at a time, while
- Lars