diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 85bfec5..1bcb4b2 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -72,6 +72,7 @@ struct serial8250_config {
 #define UART_CAP_UUE	(1 << 12)	/* UART needs IER bit 6 set (Xscale) */
 #define UART_CAP_RTOIE	(1 << 13)	/* UART needs IER bit 4 set (Xscale, Tegra) */
 #define UART_CAP_HFIFO	(1 << 14)	/* UART has a "hidden" FIFO */
+#define UART_CAP_RPM	(1 << 15)	/* Runtime PM is active while idle */
 
 #define UART_BUG_QUOT	(1 << 0)	/* UART has buggy quot LSB */
 #define UART_BUG_TXEN	(1 << 1)	/* UART has buggy TX IIR status */
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 35fe96e..ae268e3 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -37,6 +37,7 @@
 #include <linux/nmi.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 #ifdef CONFIG_SPARC
 #include <linux/sunserialcore.h>
 #endif
@@ -539,6 +540,53 @@ void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
 }
 EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
 
+static void serial8250_rpm_get(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+
+static void serial8250_rpm_put(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+
+/*
+ * This two wrapper ensure, that enable_runtime_pm_tx() can be called more than
+ * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
+ * empty and the HW can idle again.
+ */
+static void serial8250_rpm_get_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 1);
+	if (rpm_active)
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+
+static void serial8250_rpm_put_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 0);
+	if (!rpm_active)
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+
 /*
  * IER sleep support.  UARTs which have EFRs need the "extended
  * capability" bit enabled.  Note that on XR16C850s, we need to
@@ -553,10 +601,11 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 	 * offset but the UART channel may only write to the corresponding
 	 * bit.
 	 */
+	serial8250_rpm_get(p);
 	if ((p->port.type == PORT_XR17V35X) ||
 	   (p->port.type == PORT_XR17D15X)) {
 		serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0);
-		return;
+		goto out;
 	}
 
 	if (p->capabilities & UART_CAP_SLEEP) {
@@ -572,6 +621,8 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 			serial_out(p, UART_LCR, 0);
 		}
 	}
+out:
+	serial8250_rpm_put(p);
 }
 
 #ifdef CONFIG_SERIAL_8250_RSA
@@ -1272,6 +1323,7 @@ static inline void __stop_tx(struct uart_8250_port *p)
 	if (p->ier & UART_IER_THRI) {
 		p->ier &= ~UART_IER_THRI;
 		serial_out(p, UART_IER, p->ier);
+		serial8250_rpm_put_tx(p);
 	}
 }
 
@@ -1279,6 +1331,7 @@ static void serial8250_stop_tx(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
+	serial8250_rpm_get(up);
 	__stop_tx(up);
 
 	/*
@@ -1288,12 +1341,14 @@ static void serial8250_stop_tx(struct uart_port *port)
 		up->acr |= UART_ACR_TXDIS;
 		serial_icr_write(up, UART_ACR, up->acr);
 	}
+	serial8250_rpm_put(up);
 }
 
 static void serial8250_start_tx(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
+	serial8250_rpm_get_tx(up);
 	if (up->dma && !serial8250_tx_dma(up)) {
 		return;
 	} else if (!(up->ier & UART_IER_THRI)) {
@@ -1332,9 +1387,13 @@ static void serial8250_stop_rx(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
+	serial8250_rpm_get(up);
+
 	up->ier &= ~UART_IER_RLSI;
 	up->port.read_status_mask &= ~UART_LSR_DR;
 	serial_port_out(port, UART_IER, up->ier);
+
+	serial8250_rpm_put(up);
 }
 
 static void serial8250_enable_ms(struct uart_port *port)
@@ -1346,7 +1405,10 @@ static void serial8250_enable_ms(struct uart_port *port)
 		return;
 
 	up->ier |= UART_IER_MSI;
+
+	serial8250_rpm_get(up);
 	serial_port_out(port, UART_IER, up->ier);
+	serial8250_rpm_put(up);
 }
 
 /*
@@ -1468,7 +1530,12 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 
 	DEBUG_INTR("THRE...");
 
-	if (uart_circ_empty(xmit))
+	/*
+	 * With RPM enabled, we have to wait once the FIFO is empty before the
+	 * HW can go idle. So we get here once again with empty FIFO and disable
+	 * the interrupt and RPM in __stop_tx()
+	 */
+	if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
 		__stop_tx(up);
 }
 EXPORT_SYMBOL_GPL(serial8250_tx_chars);
@@ -1535,9 +1602,17 @@ EXPORT_SYMBOL_GPL(serial8250_handle_irq);
 
 static int serial8250_default_handle_irq(struct uart_port *port)
 {
-	unsigned int iir = serial_port_in(port, UART_IIR);
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int iir;
+	int ret;
 
-	return serial8250_handle_irq(port, iir);
+	serial8250_rpm_get(up);
+
+	iir = serial_port_in(port, UART_IIR);
+	ret = serial8250_handle_irq(port, iir);
+
+	serial8250_rpm_put(up);
+	return ret;
 }
 
 /*
@@ -1794,11 +1869,15 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int lsr;
 
+	serial8250_rpm_get(up);
+
 	spin_lock_irqsave(&port->lock, flags);
 	lsr = serial_port_in(port, UART_LSR);
 	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
 	spin_unlock_irqrestore(&port->lock, flags);
 
+	serial8250_rpm_put(up);
+
 	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
 }
 
@@ -1808,7 +1887,9 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
 	unsigned int status;
 	unsigned int ret;
 
+	serial8250_rpm_get(up);
 	status = serial8250_modem_status(up);
+	serial8250_rpm_put(up);
 
 	ret = 0;
 	if (status & UART_MSR_DCD)
@@ -1840,7 +1921,9 @@ static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
 
+	serial8250_rpm_get(up);
 	serial_port_out(port, UART_MCR, mcr);
+	serial8250_rpm_put(up);
 }
 
 static void serial8250_break_ctl(struct uart_port *port, int break_state)
@@ -1848,6 +1931,7 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned long flags;
 
+	serial8250_rpm_get(up);
 	spin_lock_irqsave(&port->lock, flags);
 	if (break_state == -1)
 		up->lcr |= UART_LCR_SBC;
@@ -1855,6 +1939,7 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
 		up->lcr &= ~UART_LCR_SBC;
 	serial_port_out(port, UART_LCR, up->lcr);
 	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
 }
 
 /*
@@ -1899,12 +1984,22 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits)
 
 static int serial8250_get_poll_char(struct uart_port *port)
 {
-	unsigned char lsr = serial_port_in(port, UART_LSR);
+	unsigned char lsr;
+	int status;
+
+	serial8250_rpm_get(up);
 
-	if (!(lsr & UART_LSR_DR))
-		return NO_POLL_CHAR;
+	lsr = serial_port_in(port, UART_LSR);
 
-	return serial_port_in(port, UART_RX);
+	if (!(lsr & UART_LSR_DR)) {
+		status = NO_POLL_CHAR;
+		goto out;
+	}
+
+	status = serial_port_in(port, UART_RX);
+out:
+	serial8250_rpm_put(up);
+	return status;
 }
 
 
@@ -1914,6 +2009,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	unsigned int ier;
 	struct uart_8250_port *up = up_to_u8250p(port);
 
+	serial8250_rpm_get(up);
 	/*
 	 *	First save the IER then disable the interrupts
 	 */
@@ -1935,6 +2031,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	 */
 	wait_for_xmitr(up, BOTH_EMPTY);
 	serial_port_out(port, UART_IER, ier);
+	serial8250_rpm_put(up);
 }
 
 #endif /* CONFIG_CONSOLE_POLL */
@@ -1960,6 +2057,7 @@ int serial8250_do_startup(struct uart_port *port)
 	if (port->iotype != up->cur_iotype)
 		set_io_from_upio(port);
 
+	serial8250_rpm_get(up);
 	if (port->type == PORT_16C950) {
 		/* Wake up and initialize UART */
 		up->acr = 0;
@@ -1980,7 +2078,6 @@ int serial8250_do_startup(struct uart_port *port)
 	 */
 	enable_rsa(up);
 #endif
-
 	/*
 	 * Clear the FIFO buffers and disable them.
 	 * (they will be reenabled in set_termios())
@@ -2004,7 +2101,8 @@ int serial8250_do_startup(struct uart_port *port)
 	    (serial_port_in(port, UART_LSR) == 0xff)) {
 		printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
 				   serial_index(port));
-		return -ENODEV;
+		retval = -ENODEV;
+		goto out;
 	}
 
 	/*
@@ -2089,7 +2187,7 @@ int serial8250_do_startup(struct uart_port *port)
 	} else {
 		retval = serial_link_irq_chain(up);
 		if (retval)
-			return retval;
+			goto out;
 	}
 
 	/*
@@ -2187,8 +2285,10 @@ int serial8250_do_startup(struct uart_port *port)
 		outb_p(0x80, icp);
 		inb_p(icp);
 	}
-
-	return 0;
+	retval = 0;
+out:
+	serial8250_rpm_put(up);
+	return retval;
 }
 EXPORT_SYMBOL_GPL(serial8250_do_startup);
 
@@ -2205,6 +2305,7 @@ void serial8250_do_shutdown(struct uart_port *port)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned long flags;
 
+	serial8250_rpm_get(up);
 	/*
 	 * Disable interrupts from this port
 	 */
@@ -2244,6 +2345,7 @@ void serial8250_do_shutdown(struct uart_port *port)
 	 * the IRQ chain.
 	 */
 	serial_port_in(port, UART_RX);
+	serial8250_rpm_put(up);
 
 	del_timer_sync(&up->timer);
 	up->timer.function = serial8250_timeout;
@@ -2361,6 +2463,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
+	serial8250_rpm_get(up);
 	spin_lock_irqsave(&port->lock, flags);
 
 	/*
@@ -2482,6 +2585,8 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 	serial8250_set_mctrl(port, port->mctrl);
 	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
@@ -3055,6 +3160,8 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 
 	touch_nmi_watchdog();
 
+	serial8250_rpm_get(up);
+
 	if (port->sysrq || oops_in_progress)
 		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
@@ -3091,6 +3198,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 
 	if (locked)
 		spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
 }
 
 static int __init serial8250_console_setup(struct console *co, char *options)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index c3aa004..b161eee 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -84,6 +84,7 @@ struct uart_8250_port {
 	unsigned char		mcr_mask;	/* mask of user bits */
 	unsigned char		mcr_force;	/* mask of forced bits */
 	unsigned char		cur_iotype;	/* Running I/O type */
+	unsigned char		rpm_tx_active;
 
 	/*
 	 * Some bits in registers are cleared on a read, so they must
