UA_INT_RX
int_enable &= ~UA_INT_RX;
writeb_relaxed(UA_INT_RX, dp->port.membase + UA_INTFLAG_SET);
writeb_relaxed(UA_INT_RX | UA_INT_TX,
if (int_status & UA_INT_RX)
writeb_relaxed(UA_INT_TX | UA_INT_RX,