PCH_MAX_FIFO_DEPTH
if (data->bpw_len > PCH_MAX_FIFO_DEPTH) {
head = PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE;
if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
if (n_writes > PCH_MAX_FIFO_DEPTH)
n_writes = PCH_MAX_FIFO_DEPTH;
if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH)