snd_dma_buffer_sync
void snd_dma_buffer_sync(struct snd_dma_buffer *dmab,
EXPORT_SYMBOL_GPL(snd_dma_buffer_sync);
snd_dma_buffer_sync(snd_pcm_get_dma_buf(substream), mode);
snd_dma_buffer_sync(&priv->dmatb, SNDRV_DMA_SYNC_CPU);