Name
snd_pcm_period_elapsed — 
     update the pcm status for the next period
 
Synopsis
| void snd_pcm_period_elapsed ( | struct snd_pcm_substream * substream ); | 
 
Arguments
- substream
- 
     the pcm substream instance
     
Description
   This function is called from the interrupt handler when the
   PCM has processed the period size.  It will update the current
   pointer, wake up sleepers, etc.
   
   Even if more than one periods have elapsed since the last call, you
   have to call this only once.