On Thu, Nov 13, 2008 at 4:17 PM, Mark Brown broonie@sirena.org.uk wrote:
On Thu, Nov 13, 2008 at 03:57:08PM +0100, christian pellegrin wrote:
but this really could be "playing with DMA" since I'm not sure why there is a 1 (since min_period is 2 I would guess 2 is the right value). Anyway with this change play and capture work well.
See the commit log - the underlying DMA code restricts the number of buffers that can be queued up prior to the start of DMA.
AFAIK it's limited to 2 transfers, one loaded and one running. It could beneficial to have more of them (so the DMA doesn't stop if one interrupt is delayed for too much time). But I don't know if it's so critical. A period (4k) with cd quality sound takes 23 ms to be played. An embedded system not responding to irqs for all this time probably has worse issues.