[alsa-devel] Proposal for more reliable audio DMA.

Mark Brown broonie at opensource.wolfsonmicro.com
Tue Jun 23 11:54:45 CEST 2009

On Mon, Jun 22, 2009 at 12:43:52PM -0400, Jon Smirl wrote:
> On Mon, Jun 22, 2009 at 12:27 PM, James

> > DMA transfers on sound cards are a ring buffer. There is no automatic
> > stop feature.

> I don't about all hardware, but all of the hardware I've worked with
> works both ways, ring or stop at the end.

> DMA transfers for network packets wouldn't work in the ring buffer
> model, you need the stop at the end capability.

Remember, you're working with a general purpose SoC which shares the DMA
controller with a large selection of other hardware.  A DMA controller
that's part of a sound device and can't be used in anything else doesn't
need to worry about any other applications.

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