MAX_TX_FIFO_THRESHOLD
((MAX_TX_FIFO_THRESHOLD - curTrigLevel) / 2);
((MAX_TX_FIFO_THRESHOLD - curTrigLevel) / 2);
ahp->ah_maxTxTrigLev = MAX_TX_FIFO_THRESHOLD;
ahp->ah_maxTxTrigLev = MAX_TX_FIFO_THRESHOLD >> 1;