23 Jun
2009
23 Jun
'09
11:54 a.m.
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.