diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index f84982e508c7..66fdd3b2b958 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1660,6 +1660,7 @@ static const char *uart_type(struct uart_port *port)
 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
 {
 	struct uart_state *state = drv->state + i;
+	int pm_state;
 	struct uart_port *port = state->port;
 	char stat_buf[32];
 	unsigned int status;
@@ -1682,9 +1683,16 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i)
 
 	if(capable(CAP_SYS_ADMIN))
 	{
+		mutex_lock(&state->mutex);
+		pm_state = state->pm_state;
+		if (pm_state)
+			uart_change_pm(state, 0);
 		spin_lock_irq(&port->lock);
 		status = port->ops->get_mctrl(port);
 		spin_unlock_irq(&port->lock);
+		if (pm_state)
+			uart_change_pm(state, pm_state);
+		mutex_unlock(&state->mutex);
 
 		ret += sprintf(buf + ret, " tx:%d rx:%d",
 				port->icount.tx, port->icount.rx);
@@ -2100,6 +2108,9 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 
 		uart_report_port(drv, port);
 
+		/* Power up port for set_mctrl() */
+		uart_change_pm(state, 0);
+
 		/*
 		 * Ensure that the modem control lines are de-activated.
 		 * We probably don't need a spinlock around this, but