LS1X_DMADESC_NEXT
prev->hw[LS1X_DMADESC_NEXT] =
lli->hw[LS1X_DMADESC_NEXT] = first->phys | LS1X_DMA_NEXT_VALID;
next_phys = chan->curr_lli->hw[LS1X_DMADESC_NEXT];
if (lli->hw[LS1X_DMADESC_NEXT] == next_phys)