dbdma_insert_stop
dbdma_insert_stop(dma->channel, dma->slots + 1);
void dbdma_insert_stop(dbdma_channel_t *chan, int slot);
dbdma_insert_stop(sc->dbdma, sc->next_dma_slot++);
dbdma_insert_stop(sc->dbdma, 0);
dbdma_insert_stop(sc->dbdma,0);