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

[Jon Smirl]

On Tue, Jun 23, 2009 at 5:54 AM, Mark
Brown<broonie at opensource.wolfsonmicro.com> wrote:
> 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.
>