On Fri, May 25, 2012 at 7:20 PM, Vinod Koul vinod.koul@linux.intel.com wrote:
Nobody seems to be working on it as far as I can tell, I've certainly not seen any patches.
If so, could you accept current platform/machine driver ?
Ideally what would be happening here is that you or other people who have such systems would be working to add the required support to the core code, there's clearly a need for common code here as there are a number of different systems that don't have cyclic DMA and it wouldn't be great to end up with duplicated code.
Is there some great difficulty in factoring out the support for non-cyclic audio DMA on dmaengine - it seems like if there is we must have a serious problem in dmaengine which we should fix? If there is a substantial difficulty then that's different but it doesn't feel like we've tried doing common code yet, if there's problems doing that I'd like to understand what they are before we jump ahead of ourselves.
I'm not so familiar with Linux's DMA idea. So we don't know whether non-cyclic dmaengine has problem or not.
First you should not be writing your own dma driver, it *needs* to use dmaenegine. We already have bunch of driver supported, so there may be a case that existing driver works straight or with little modifications. Using your own dma driver is a dead road, so sooner you move over better it is.
I've never developed our own dma driver. I've developed our ASoC driver using linux standard DMA framework.