[alsa-devel] [PATCH] ASoC: s3c24xx platform: Fix s3c2410_dma_started called at wrong time

[Mark Brown]

On Thu, Aug 20, 2009 at 09:38:00PM +0800, Shine Liu wrote:

> Callback is a elegant way to solve the problem. But I have a question
> that when should the DMA driver call the callback funtion? There is no
> event to tell it to call. Periodly checking? It will not only cause
> latency but also increase the system load. 

The callback doesn't need to be set up within the trigger function - if
it's done before the trigger functions are called then the DMA trigger
can call it.  Off the top of my head I'd expect it's possible to set it
up when the device is opened.