UART_17158_TX_AND_FIFO_CLR
if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {