diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 1127586dbc94..72aab1b05265 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -107,7 +107,6 @@
 static void lqasc_tx_chars(struct uart_port *port);
 static struct ltq_uart_port *lqasc_port[MAXPORTS];
 static struct uart_driver lqasc_reg;
-static DEFINE_SPINLOCK(ltq_asc_lock);
 
 struct ltq_uart_port {
 	struct uart_port	port;
@@ -118,6 +117,7 @@ struct ltq_uart_port {
 	unsigned int		tx_irq;
 	unsigned int		rx_irq;
 	unsigned int		err_irq;
+	spinlock_t		lock;  /* exclusive access for multi core */
 };
 
 static inline struct ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
@@ -133,10 +133,11 @@ static void lqasc_stop_tx(struct uart_port *port)
 static void lqasc_start_tx(struct uart_port *port)
 {
 	unsigned long flags;
-	spin_lock_irqsave(&ltq_asc_lock, flags);
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
 	lqasc_tx_chars(port);
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
-	return;
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
 }
 
 static void lqasc_stop_rx(struct uart_port *port)
@@ -238,10 +239,14 @@ static irqreturn_t lqasc_tx_int(int irq, void *_port)
 {
 	unsigned long flags;
 	struct uart_port *port = (struct uart_port *)_port;
-	spin_lock_irqsave(&ltq_asc_lock, flags);
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
 	writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
 	lqasc_start_tx(port);
+
 	return IRQ_HANDLED;
 }
 
@@ -250,8 +255,9 @@ static irqreturn_t lqasc_err_int(int irq, void *_port)
 	unsigned long flags;
 	u32 stat;
 	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 
-	spin_lock_irqsave(&ltq_asc_lock, flags);
+	spin_lock_irqsave(&ltq_port->lock, flags);
 	/* clear any pending interrupts */
 	writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
 	stat = readl(port->membase + LTQ_ASC_STATE);
@@ -266,7 +272,7 @@ static irqreturn_t lqasc_err_int(int irq, void *_port)
 		port->icount.overrun++;
 	}
 	asc_w32_mask(0, ASCWHBSTATE_CLRALL, port->membase + LTQ_ASC_WHBSTATE);
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
 
 	return IRQ_HANDLED;
 }
@@ -275,10 +281,13 @@ static irqreturn_t lqasc_rx_int(int irq, void *_port)
 {
 	unsigned long flags;
 	struct uart_port *port = (struct uart_port *)_port;
-	spin_lock_irqsave(&ltq_asc_lock, flags);
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
 	writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
 	lqasc_rx_chars(port);
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
 	return IRQ_HANDLED;
 }
 
@@ -309,11 +318,13 @@ lqasc_startup(struct uart_port *port)
 {
 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 	int retval;
+	unsigned long flags;
 
 	if (!IS_ERR(ltq_port->clk))
 		clk_enable(ltq_port->clk);
 	port->uartclk = clk_get_rate(ltq_port->fpiclk);
 
+	spin_lock_irqsave(&ltq_port->lock, flags);
 	asc_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
 		port->membase + LTQ_ASC_CLC);
 
@@ -330,6 +341,7 @@ lqasc_startup(struct uart_port *port)
 	wmb();
 	asc_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
 		     ASCCON_ROEN, port->membase + LTQ_ASC_CON);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
 
 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
 			     0, "asc_tx", port);
@@ -410,6 +422,7 @@ static void lqasc_set_termios(struct uart_port *port,
 	unsigned long flags;
 	u32 fdv = 0;
 	u32 reload = 0;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 
 	cflag = new->c_cflag;
 	iflag = new->c_iflag;
@@ -463,7 +476,7 @@ static void lqasc_set_termios(struct uart_port *port,
 	/* set error signals  - framing, parity  and overrun, enable receiver */
 	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
 
-	spin_lock_irqsave(&ltq_asc_lock, flags);
+	spin_lock_irqsave(&ltq_port->lock, flags);
 
 	/* set up CON */
 	asc_w32_mask(0, con, port->membase + LTQ_ASC_CON);
@@ -490,7 +503,7 @@ static void lqasc_set_termios(struct uart_port *port,
 	/* enable rx */
 	writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
 
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
 
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(new))
@@ -604,16 +617,14 @@ static void lqasc_console_putchar(struct uart_port *port, int ch)
 static void lqasc_serial_port_write(struct uart_port *port, const char *s,
 				    u_int count)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&ltq_asc_lock, flags);
 	uart_console_write(port, s, count, lqasc_console_putchar);
-	spin_unlock_irqrestore(&ltq_asc_lock, flags);
 }
 
 static void lqasc_console_write(struct console *co, const char *s, u_int count)
 {
+	unsigned long flags;
 	struct ltq_uart_port *ltq_port;
+	struct uart_port *port;
 
 	if (co->index >= MAXPORTS)
 		return;
@@ -622,7 +633,11 @@ static void lqasc_console_write(struct console *co, const char *s, u_int count)
 	if (!ltq_port)
 		return;
 
-	lqasc_serial_port_write(&ltq_port->port, s, count);
+	port = &ltq_port->port;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	lqasc_serial_port_write(port, s, count);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
 }
 
 static int __init lqasc_console_setup(struct console *co, char *options)
@@ -760,6 +775,8 @@ static int __init lqasc_probe(struct platform_device *pdev)
 	ltq_port->rx_irq = irqres[1].start;
 	ltq_port->err_irq = irqres[2].start;
 
+	spin_lock_init(&ltq_port->lock);
+
 	lqasc_port[line] = ltq_port;
 	platform_set_drvdata(pdev, ltq_port);
 
