diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 56ccbcefdd85..4feb9ed92d7c 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1563,9 +1563,17 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	DEBUG_INTR("status = %x...", status);
 
 	if (status & (UART_LSR_DR | UART_LSR_BI)) {
-		if (up->dma)
-			dma_err = up->dma->rx_dma(up, iir);
+		if (up->dma) {
+			/*
+			 * The RDI must be masked, or interrupt
+			 * would occur all the time.
+			 */
+			up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+			up->port.read_status_mask &= ~UART_LSR_DR;
+			serial_port_out(port, UART_IER, up->ier);
 
+			dma_err = up->dma->rx_dma(up, iir);
+		}
 		if (!up->dma || dma_err)
 			status = serial8250_rx_chars(up, status);
 	}
@@ -2355,6 +2363,9 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial8250_set_divisor(port, baud, quot, frac);
 
+	if (up->dma)
+		up->fcr = UART_FCR_ENABLE_FIFO | UART_FCR_T_TRIG_11;
+
 	/*
 	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
 	 * is written without DLAB set, this mode will be disabled.