[alsa-devel] Trigger problems while writing Alsa Shim

[bruce at azbarclay.com]

I am writing a shim from alsa to our own sound card drivers.  I was  
able to get the init driver working and our sound card recognized.   
Things seem to be set up correctly.  When I do aplay to my device (USB  
device works find), it calls my copy callback twice and then it calls  
the trigger and fails.  The call that fails is in pcm_write  
(writei_func) with a -5.  I know that my callback returns zero but  
there must be something else under the covers since that gets to be  
zero.  Any help would be appreciated.
T