[twobob]

BUG: (noted at http://elinux.org/RidgeRun_LeopardBoard_SDK_Hints

To Check for this simply run

arecord -D 'plughw' -r 8000 -f S16_LE -c 2 | aplay -D 'plughw'

nothing happens, now try

aplay somefile.wav

THEN (GET READY TO TURN THE VOLUME DOWN)

arecord -D 'plughw' -r 8000 -f S16_LE -c 2 | aplay -D 'plughw'

now you can see the pipe works correctly
This seems to be as the result of a "'division by zero' in kernel error " on other systems so that's probably a good lead.

I think we may have a possible link to a solution (well roughly)

 Solutions to known issues
'division by zero' in kernel error when I try to use ALSA input

This is a known issue that has been discussed on the ASOC mailing list. 
The problem is that the function davinci_pcm_enqueue_dma performs this operations:

data_type = prtd->params->data_type;
count = period_size / data_type;

The first time, data_type is set to zero, so we get the error Division by zero in kernel. 
This is the reason why the pipe arecord | aplay works after running arecord or aplay first.

Apply the Media:Asoc-davinci-pcm.patch 
<http://elinux.org/images/9/95/Asoc-davinci-pcm.patch> 
to the kernel 2.6.29 to resolve this issue.

So I will have a look at that at some point but good to know I have a quick fix for instancing the soundcard, at our command, in full-duplex now at least.

so happy days there.

FULL-DUPLEX is GO (okay with some wangles and a reliant on two native apps but it should pave the way for some interesting piping hey Geekmaster

THIS IS THE REASON THE OTHER VOIP APPLICATION DIDN'T WORK I THINK
I am thinking of making it run through dmix0 now. that may have value.

in the interim. aplay > blank.wav; causes the card to snap out of it, it would seem