diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 20c610440133..d91f76b1d353 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -280,16 +280,17 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
 {
 	struct uart_port *port = data;
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned long flags;
 	unsigned int isr;
 
 	isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 
-	spin_lock(&port->lock);
+	spin_lock_irqsave(&port->lock, flags);
 	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
 		altera_uart_rx_chars(port);
 	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
 		altera_uart_tx_chars(port);
-	spin_unlock(&port->lock);
+	spin_unlock_irqrestore(&port->lock, flags);
 
 	return IRQ_RETVAL(isr);
 }