TxThreshold
writel(++np->tx_threshold, np->base + TxThreshold);
writel(np->tx_threshold, ioaddr + TxThreshold);
if (negotiated & LPA_100) new_csr6 &= ~TxThreshold;
else new_csr6 |= TxThreshold;
iowrite32(yp->tx_threshold, ioaddr + TxThreshold);