[alsa-devel] pcm_prepare, and pcm_trigger

[John Kacur]

On Tue, Nov 25, 2008 at 3:48 PM, Mark Brown <broonie at sirena.org.uk> wrote:
> On Tue, Nov 25, 2008 at 02:59:46PM +0100, John Kacur wrote:
>
>> cat 8k8bitpcm.wav > /dev/dsp
>
>>         myplatform_pcm_prepare,
>>        myplatform_pcm_trigger
>
>> Is this normal? Who calls these functions?
>
> I'd expect to see those called.  They're called by the core in response
> to ALSA API operations - since you're using /dev/dsp the actual ALSA API
> client will be the OSS emulation you're using (normally the in-kernel
> one).  For the purposes of development it's generally easier if you work
> with the ALSA APIs and use utilities like aplay to test.  This avoids
> the layer of indirection added by OSS emulation, making bringup a bit
> clearer.
>

Thanks again for the info.

On the embedded board I'm working on, compiling the alsa utilities
isn't an option, we have the OSS emulation as a requirement.