[alsa-devel] Basic DMA question

Rene Herman rene.herman at gmail.com
Wed Mar 28 12:47:03 CEST 2007

On 03/28/2007 12:16 PM, Takashi Iwai wrote:

> At Mon, 26 Mar 2007 11:28:59 +0200,
> Sven Johnsson wrote:

>> Rene,
>> I have already read the ALSA driver document. What I really like to
>> understand is when DMA transfers are invoked, and what the source and
>> destination for the transfer is.
> The DMA transfer is started/stopped in trigger callback.
> In the case of typical playback, the source is the buffer the driver
> allocated (in hw_params callback) and the destination is the
> hardware.  The DMA setup is usually done in prepare callback.

Oh, sorry... had to look at this one before answering but then forgot 
about it while looking at a local capture problem.


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