On Thu, May 24, 2012 at 7:07 PM, Mark Brown broonie@opensource.wolfsonmicro.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.
Until now, we've developed device drivers use DMA driver like UART, SPI. These drivers are implemented using the same way, you called "non-cyclic", and already applied.
As you said, common code for DMA code can be best solution. However, currently, the code is nothing. So, I want you to accept our driver as first step. Because I think supporting new device is more important for linux than dmaengine common.
thanks