Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (65 commits)
  tty: serial: imx: move del_timer_sync() to avoid potential deadlock
  imx: add polled io uart methods
  imx: Add save/restore functions for UART control regs
  serial/imx: let probing fail for the dt case without a valid alias
  serial/imx: propagate error from of_alias_get_id instead of using -ENODEV
  tty: serial: imx: Allow UART to be a source for wakeup
  serial: driver for m32 arch should not have DEC alpha errata
  serial/documentation: fix documented name of DCD cpp symbol
  atmel_serial: fix spinlock lockup in RS485 code
  tty: Fix memory leak in virtual console when enable unicode translation
  serial: use DIV_ROUND_CLOSEST instead of open coding it
  serial: add support for 400 and 800 v3 series Titan cards
  serial: bfin-uart: Remove ASYNC_CTS_FLOW flag for hardware automatic CTS.
  serial: bfin-uart: Enable hardware automatic CTS only when CTS pin is available.
  serial: make FSL errata depend on 8250_CONSOLE, not just 8250
  serial: add irq handler for Freescale 16550 errata.
  serial: manually inline serial8250_handle_port
  serial: make 8250 timeout use the specified IRQ handler
  serial: export the key functions for an 8250 IRQ handler
  serial: clean up parameter passing for 8250 Rx IRQ handling
  ...

45 files changed, 1989 insertions, 658 deletions

diff --git a/Documentation/serial/driver b/Documentation/serial/driver
index 77ba0afbe4db..0a25a9191864 100644
--- a/Documentation/serial/driver
+++ b/Documentation/serial/driver
@@ -101,7 +101,7 @@ hardware.
 	Returns the current state of modem control inputs.  The state
 	of the outputs should not be returned, since the core keeps
 	track of their state.  The state information should include:
-		- TIOCM_DCD	state of DCD signal
+		- TIOCM_CAR	state of DCD signal
 		- TIOCM_CTS	state of CTS signal
 		- TIOCM_DSR	state of DSR signal
 		- TIOCM_RI	state of RI signal
diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index c7b5afeecaf2..3fea3689527e 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -441,6 +441,9 @@ static void __init fixup_port_irq(int index,
 		return;
 
 	port->irq = virq;
+
+	if (of_device_is_compatible(np, "fsl,ns16550"))
+		port->handle_irq = fsl8250_handle_irq;
 }
 
 static void __init fixup_port_pio(int index,
diff --git a/arch/x86/include/asm/mrst.h b/arch/x86/include/asm/mrst.h
index 93f79094c224..0a0a95460434 100644
--- a/arch/x86/include/asm/mrst.h
+++ b/arch/x86/include/asm/mrst.h
@@ -67,7 +67,7 @@ extern struct console early_mrst_console;
 extern void mrst_early_console_init(void);
 
 extern struct console early_hsu_console;
-extern void hsu_early_console_init(void);
+extern void hsu_early_console_init(const char *);
 
 extern void intel_scu_devices_create(void);
 extern void intel_scu_devices_destroy(void);
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index cd28a350f7f9..9d42a52d2331 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -247,7 +247,7 @@ static int __init setup_early_printk(char *buf)
 		}
 
 		if (!strncmp(buf, "hsu", 3)) {
-			hsu_early_console_init();
+			hsu_early_console_init(buf + 3);
 			early_console_register(&early_hsu_console, keep);
 		}
 #endif
diff --git a/arch/x86/platform/mrst/early_printk_mrst.c b/arch/x86/platform/mrst/early_printk_mrst.c
index 25bfdbb5b130..3c6e328483c7 100644
--- a/arch/x86/platform/mrst/early_printk_mrst.c
+++ b/arch/x86/platform/mrst/early_printk_mrst.c
@@ -245,16 +245,24 @@ struct console early_mrst_console = {
  * Following is the early console based on Medfield HSU (High
  * Speed UART) device.
  */
-#define HSU_PORT2_PADDR		0xffa28180
+#define HSU_PORT_BASE		0xffa28080
 
 static void __iomem *phsu;
 
-void hsu_early_console_init(void)
+void hsu_early_console_init(const char *s)
 {
+	unsigned long paddr, port = 0;
 	u8 lcr;
 
-	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-							HSU_PORT2_PADDR);
+	/*
+	 * Select the early HSU console port if specified by user in the
+	 * kernel command line.
+	 */
+	if (*s && !kstrtoul(s, 10, &port))
+		port = clamp_val(port, 0, 2);
+
+	paddr = HSU_PORT_BASE + port * 0x80;
+	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
 
 	/* Disable FIFO */
 	writeb(0x0, phsu + UART_FCR);
diff --git a/drivers/parport/parport_ax88796.c b/drivers/parport/parport_ax88796.c
index 844f6137970a..7c5d86696eed 100644
--- a/drivers/parport/parport_ax88796.c
+++ b/drivers/parport/parport_ax88796.c
@@ -420,18 +420,7 @@ static struct platform_driver axdrv = {
 	.resume		= parport_ax88796_resume,
 };
 
-static int __init parport_ax88796_init(void)
-{
-	return platform_driver_register(&axdrv);
-}
-
-static void __exit parport_ax88796_exit(void)
-{
-	platform_driver_unregister(&axdrv);
-}
-
-module_init(parport_ax88796_init)
-module_exit(parport_ax88796_exit)
+module_platform_driver(axdrv);
 
 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 MODULE_DESCRIPTION("AX88796 Parport parallel port driver");
diff --git a/drivers/parport/parport_sunbpp.c b/drivers/parport/parport_sunbpp.c
index 910c5a26e347..9390a534a2b2 100644
--- a/drivers/parport/parport_sunbpp.c
+++ b/drivers/parport/parport_sunbpp.c
@@ -391,21 +391,10 @@ static struct platform_driver bpp_sbus_driver = {
 	.remove		= __devexit_p(bpp_remove),
 };
 
-static int __init parport_sunbpp_init(void)
-{
-	return platform_driver_register(&bpp_sbus_driver);
-}
-
-static void __exit parport_sunbpp_exit(void)
-{
-	platform_driver_unregister(&bpp_sbus_driver);
-}
+module_platform_driver(bpp_sbus_driver);
 
 MODULE_AUTHOR("Derrick J Brashear");
 MODULE_DESCRIPTION("Parport Driver for Sparc bidirectional Port");
 MODULE_SUPPORTED_DEVICE("Sparc Bidirectional Parallel Port");
 MODULE_VERSION("2.0");
 MODULE_LICENSE("GPL");
-
-module_init(parport_sunbpp_init)
-module_exit(parport_sunbpp_exit)
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index cea56033b34c..a09ce3ef5d74 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -417,7 +417,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
 				__FILE__,__LINE__,tbuf,tbuf->count);
 			
 		/* Send the next block of data to device */
-		tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 		actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
 
 		/* rollback was possible and has been done */
@@ -459,7 +459,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
 	}
 	
 	if (!tbuf)
-		tty->flags  &= ~(1 << TTY_DO_WRITE_WAKEUP);
+		clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	
 	/* Clear the re-entry flag */
 	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
@@ -491,7 +491,7 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
 		return;
 
 	if (tty != n_hdlc->tty) {
-		tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+		clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 		return;
 	}
 
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 39d6ab6551e0..d2256d08ee7e 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -61,7 +61,7 @@
  * controlling the space in the read buffer.
  */
 #define TTY_THRESHOLD_THROTTLE		128 /* now based on remaining room */
-#define TTY_THRESHOLD_UNTHROTTLE 	128
+#define TTY_THRESHOLD_UNTHROTTLE	128
 
 /*
  * Special byte codes used in the echo buffer to represent operations
@@ -405,7 +405,7 @@ static ssize_t process_output_block(struct tty_struct *tty,
 				    const unsigned char *buf, unsigned int nr)
 {
 	int	space;
-	int 	i;
+	int	i;
 	const unsigned char *cp;
 
 	mutex_lock(&tty->output_lock);
@@ -1607,7 +1607,7 @@ static inline int input_available_p(struct tty_struct *tty, int amt)
 }
 
 /**
- * 	copy_from_read_buf	-	copy read data directly
+ *	copy_from_read_buf	-	copy read data directly
  *	@tty: terminal device
  *	@b: user data
  *	@nr: size of data
@@ -1909,7 +1909,7 @@ do_it_again:
 		if (nr)
 			clear_bit(TTY_PUSH, &tty->flags);
 	} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
-		 goto do_it_again;
+		goto do_it_again;
 
 	n_tty_set_room(tty);
 	return retval;
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index e18604b3fc7d..d8653ab6f498 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -446,19 +446,8 @@ static inline void legacy_pty_init(void) { }
 int pty_limit = NR_UNIX98_PTY_DEFAULT;
 static int pty_limit_min;
 static int pty_limit_max = NR_UNIX98_PTY_MAX;
-static int tty_count;
 static int pty_count;
 
-static inline void pty_inc_count(void)
-{
-	pty_count = (++tty_count) / 2;
-}
-
-static inline void pty_dec_count(void)
-{
-	pty_count = (--tty_count) / 2;
-}
-
 static struct cdev ptmx_cdev;
 
 static struct ctl_table pty_table[] = {
@@ -600,8 +589,7 @@ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
 	 */
 	tty_driver_kref_get(driver);
 	tty->count++;
-	pty_inc_count(); /* tty */
-	pty_inc_count(); /* tty->link */
+	pty_count++;
 	return 0;
 err_free_mem:
 	deinitialize_tty_struct(o_tty);
@@ -613,15 +601,19 @@ err_free_tty:
 	return -ENOMEM;
 }
 
-static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
+static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+	pty_count--;
+}
+
+static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
 {
-	pty_dec_count();
 }
 
 static const struct tty_operations ptm_unix98_ops = {
 	.lookup = ptm_unix98_lookup,
 	.install = pty_unix98_install,
-	.remove = pty_unix98_remove,
+	.remove = ptm_unix98_remove,
 	.open = pty_open,
 	.close = pty_close,
 	.write = pty_write,
@@ -638,7 +630,7 @@ static const struct tty_operations ptm_unix98_ops = {
 static const struct tty_operations pty_unix98_ops = {
 	.lookup = pts_unix98_lookup,
 	.install = pty_unix98_install,
-	.remove = pty_unix98_remove,
+	.remove = pts_unix98_remove,
 	.open = pty_open,
 	.close = pty_close,
 	.write = pty_write,
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index eeadf1b8e093..9f50c4e3c2be 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -129,32 +129,6 @@ static unsigned long probe_rsa[PORT_RSA_MAX];
 static unsigned int probe_rsa_count;
 #endif /* CONFIG_SERIAL_8250_RSA  */
 
-struct uart_8250_port {
-	struct uart_port	port;
-	struct timer_list	timer;		/* "no irq" timer */
-	struct list_head	list;		/* ports on this IRQ */
-	unsigned short		capabilities;	/* port capabilities */
-	unsigned short		bugs;		/* port bugs */
-	unsigned int		tx_loadsz;	/* transmit fifo load size */
-	unsigned char		acr;
-	unsigned char		ier;
-	unsigned char		lcr;
-	unsigned char		mcr;
-	unsigned char		mcr_mask;	/* mask of user bits */
-	unsigned char		mcr_force;	/* mask of forced bits */
-	unsigned char		cur_iotype;	/* Running I/O type */
-
-	/*
-	 * Some bits in registers are cleared on a read, so they must
-	 * be saved whenever the register is read but the bits will not
-	 * be immediately processed.
-	 */
-#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
-	unsigned char		lsr_saved_flags;
-#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
-	unsigned char		msr_saved_flags;
-};
-
 struct irq_info {
 	struct			hlist_node node;
 	int			irq;
@@ -1326,8 +1300,6 @@ static void serial8250_stop_tx(struct uart_port *port)
 	}
 }
 
-static void transmit_chars(struct uart_8250_port *up);
-
 static void serial8250_start_tx(struct uart_port *port)
 {
 	struct uart_8250_port *up =
@@ -1344,7 +1316,7 @@ static void serial8250_start_tx(struct uart_port *port)
 			if ((up->port.type == PORT_RM9000) ?
 				(lsr & UART_LSR_THRE) :
 				(lsr & UART_LSR_TEMT))
-				transmit_chars(up);
+				serial8250_tx_chars(up);
 		}
 	}
 
@@ -1401,11 +1373,16 @@ static void clear_rx_fifo(struct uart_8250_port *up)
 	} while (1);
 }
 
-static void
-receive_chars(struct uart_8250_port *up, unsigned int *status)
+/*
+ * serial8250_rx_chars: processes according to the passed in LSR
+ * value, and returns the remaining LSR bits not handled
+ * by this Rx routine.
+ */
+unsigned char
+serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
 {
 	struct tty_struct *tty = up->port.state->port.tty;
-	unsigned char ch, lsr = *status;
+	unsigned char ch;
 	int max_count = 256;
 	char flag;
 
@@ -1481,10 +1458,11 @@ ignore_char:
 	spin_unlock(&up->port.lock);
 	tty_flip_buffer_push(tty);
 	spin_lock(&up->port.lock);
-	*status = lsr;
+	return lsr;
 }
+EXPORT_SYMBOL_GPL(serial8250_rx_chars);
 
-static void transmit_chars(struct uart_8250_port *up)
+void serial8250_tx_chars(struct uart_8250_port *up)
 {
 	struct circ_buf *xmit = &up->port.state->xmit;
 	int count;
@@ -1521,8 +1499,9 @@ static void transmit_chars(struct uart_8250_port *up)
 	if (uart_circ_empty(xmit))
 		__stop_tx(up);
 }
+EXPORT_SYMBOL_GPL(serial8250_tx_chars);
 
-static unsigned int check_modem_status(struct uart_8250_port *up)
+unsigned int serial8250_modem_status(struct uart_8250_port *up)
 {
 	unsigned int status = serial_in(up, UART_MSR);
 
@@ -1544,14 +1523,20 @@ static unsigned int check_modem_status(struct uart_8250_port *up)
 
 	return status;
 }
+EXPORT_SYMBOL_GPL(serial8250_modem_status);
 
 /*
  * This handles the interrupt from one port.
  */
-static void serial8250_handle_port(struct uart_8250_port *up)
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 {
-	unsigned int status;
+	unsigned char status;
 	unsigned long flags;
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	if (iir & UART_IIR_NO_INT)
+		return 0;
 
 	spin_lock_irqsave(&up->port.lock, flags);
 
@@ -1560,25 +1545,13 @@ static void serial8250_handle_port(struct uart_8250_port *up)
 	DEBUG_INTR("status = %x...", status);
 
 	if (status & (UART_LSR_DR | UART_LSR_BI))
-		receive_chars(up, &status);
-	check_modem_status(up);
+		status = serial8250_rx_chars(up, status);
+	serial8250_modem_status(up);
 	if (status & UART_LSR_THRE)
-		transmit_chars(up);
+		serial8250_tx_chars(up);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
-}
-
-int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
-{
-	struct uart_8250_port *up =
-		container_of(port, struct uart_8250_port, port);
-
-	if (!(iir & UART_IIR_NO_INT)) {
-		serial8250_handle_port(up);
-		return 1;
-	}
-
-	return 0;
+	return 1;
 }
 EXPORT_SYMBOL_GPL(serial8250_handle_irq);
 
@@ -1619,11 +1592,13 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 	do {
 		struct uart_8250_port *up;
 		struct uart_port *port;
+		bool skip;
 
 		up = list_entry(l, struct uart_8250_port, list);
 		port = &up->port;
+		skip = pass_counter && up->port.flags & UPF_IIR_ONCE;
 
-		if (port->handle_irq(port)) {
+		if (!skip && port->handle_irq(port)) {
 			handled = 1;
 			end = NULL;
 		} else if (end == NULL)
@@ -1758,11 +1733,8 @@ static void serial_unlink_irq_chain(struct uart_8250_port *up)
 static void serial8250_timeout(unsigned long data)
 {
 	struct uart_8250_port *up = (struct uart_8250_port *)data;
-	unsigned int iir;
 
-	iir = serial_in(up, UART_IIR);
-	if (!(iir & UART_IIR_NO_INT))
-		serial8250_handle_port(up);
+	up->port.handle_irq(&up->port);
 	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
 }
 
@@ -1801,7 +1773,7 @@ static void serial8250_backup_timeout(unsigned long data)
 	}
 
 	if (!(iir & UART_IIR_NO_INT))
-		transmit_chars(up);
+		serial8250_tx_chars(up);
 
 	if (is_real_interrupt(up->port.irq))
 		serial_out(up, UART_IER, ier);
@@ -1835,7 +1807,7 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
 	unsigned int status;
 	unsigned int ret;
 
-	status = check_modem_status(up);
+	status = serial8250_modem_status(up);
 
 	ret = 0;
 	if (status & UART_MSR_DCD)
@@ -2000,7 +1972,7 @@ static int serial8250_startup(struct uart_port *port)
 		serial_outp(up, UART_IER, 0);
 		serial_outp(up, UART_LCR, 0);
 		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
-		serial_outp(up, UART_LCR, 0xBF);
+		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_outp(up, UART_EFR, UART_EFR_ECB);
 		serial_outp(up, UART_LCR, 0);
 	}
@@ -2848,7 +2820,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 
 	local_irq_save(flags);
 	if (up->port.sysrq) {
-		/* serial8250_handle_port() already took the lock */
+		/* serial8250_handle_irq() already took the lock */
 		locked = 0;
 	} else if (oops_in_progress) {
 		locked = spin_trylock(&up->port.lock);
@@ -2882,7 +2854,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 	 *	while processing with interrupts off.
 	 */
 	if (up->msr_saved_flags)
-		check_modem_status(up);
+		serial8250_modem_status(up);
 
 	if (locked)
 		spin_unlock(&up->port.lock);
diff --git a/drivers/tty/serial/8250.h b/drivers/tty/serial/8250.h
index 6edf4a6a22d4..ae027be57e25 100644
--- a/drivers/tty/serial/8250.h
+++ b/drivers/tty/serial/8250.h
@@ -13,6 +13,32 @@
 
 #include <linux/serial_8250.h>
 
+struct uart_8250_port {
+	struct uart_port	port;
+	struct timer_list	timer;		/* "no irq" timer */
+	struct list_head	list;		/* ports on this IRQ */
+	unsigned short		capabilities;	/* port capabilities */
+	unsigned short		bugs;		/* port bugs */
+	unsigned int		tx_loadsz;	/* transmit fifo load size */
+	unsigned char		acr;
+	unsigned char		ier;
+	unsigned char		lcr;
+	unsigned char		mcr;
+	unsigned char		mcr_mask;	/* mask of user bits */
+	unsigned char		mcr_force;	/* mask of forced bits */
+	unsigned char		cur_iotype;	/* Running I/O type */
+
+	/*
+	 * Some bits in registers are cleared on a read, so they must
+	 * be saved whenever the register is read but the bits will not
+	 * be immediately processed.
+	 */
+#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
+	unsigned char		lsr_saved_flags;
+#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
+	unsigned char		msr_saved_flags;
+};
+
 struct old_serial_port {
 	unsigned int uart;
 	unsigned int baud_base;
diff --git a/drivers/tty/serial/8250_dw.c b/drivers/tty/serial/8250_dw.c
index bf1fba640c2d..f574eef3075f 100644
--- a/drivers/tty/serial/8250_dw.c
+++ b/drivers/tty/serial/8250_dw.c
@@ -177,17 +177,7 @@ static struct platform_driver dw8250_platform_driver = {
 	.remove			= __devexit_p(dw8250_remove),
 };
 
-static int __init dw8250_init(void)
-{
-	return platform_driver_register(&dw8250_platform_driver);
-}
-module_init(dw8250_init);
-
-static void __exit dw8250_exit(void)
-{
-	platform_driver_unregister(&dw8250_platform_driver);
-}
-module_exit(dw8250_exit);
+module_platform_driver(dw8250_platform_driver);
 
 MODULE_AUTHOR("Jamie Iles");
 MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250_fsl.c b/drivers/tty/serial/8250_fsl.c
new file mode 100644
index 000000000000..f4d3c47b88e8
--- /dev/null
+++ b/drivers/tty/serial/8250_fsl.c
@@ -0,0 +1,63 @@
+#include <linux/serial_reg.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+/*
+ * Freescale 16550 UART "driver", Copyright (C) 2011 Paul Gortmaker.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This isn't a full driver; it just provides an alternate IRQ
+ * handler to deal with an errata.  Everything else is just
+ * using the bog standard 8250 support.
+ *
+ * We follow code flow of serial8250_default_handle_irq() but add
+ * a check for a break and insert a dummy read on the Rx for the
+ * immediately following IRQ event.
+ *
+ * We re-use the already existing "bug handling" lsr_saved_flags
+ * field to carry the "what we just did" information from the one
+ * IRQ event to the next one.
+ */
+
+int fsl8250_handle_irq(struct uart_port *port)
+{
+	unsigned char lsr, orig_lsr;
+	unsigned long flags;
+	unsigned int iir;
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	iir = port->serial_in(port, UART_IIR);
+	if (iir & UART_IIR_NO_INT) {
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return 0;
+	}
+
+	/* This is the WAR; if last event was BRK, then read and return */
+	if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
+		up->lsr_saved_flags &= ~UART_LSR_BI;
+		port->serial_in(port, UART_RX);
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return 1;
+	}
+
+	lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
+
+	if (lsr & (UART_LSR_DR | UART_LSR_BI))
+		lsr = serial8250_rx_chars(up, lsr);
+
+	serial8250_modem_status(up);
+
+	if (lsr & UART_LSR_THRE)
+		serial8250_tx_chars(up);
+
+	up->lsr_saved_flags = orig_lsr;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	return 1;
+}
diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c
index 825937a5f210..da2b0b0a183f 100644
--- a/drivers/tty/serial/8250_pci.c
+++ b/drivers/tty/serial/8250_pci.c
@@ -1092,6 +1092,14 @@ static int skip_tx_en_setup(struct serial_private *priv,
 	return pci_default_setup(priv, board, port, idx);
 }
 
+static int kt_serial_setup(struct serial_private *priv,
+			   const struct pciserial_board *board,
+			   struct uart_port *port, int idx)
+{
+	port->flags |= UPF_IIR_ONCE;
+	return skip_tx_en_setup(priv, board, port, idx);
+}
+
 static int pci_eg20t_init(struct pci_dev *dev)
 {
 #if defined(CONFIG_SERIAL_PCH_UART) || defined(CONFIG_SERIAL_PCH_UART_MODULE)
@@ -1110,7 +1118,18 @@ pci_xr17c154_setup(struct serial_private *priv,
 	return pci_default_setup(priv, board, port, idx);
 }
 
-/* This should be in linux/pci_ids.h */
+static int try_enable_msi(struct pci_dev *dev)
+{
+	/* use msi if available, but fallback to legacy otherwise */
+	pci_enable_msi(dev);
+	return 0;
+}
+
+static void disable_msi(struct pci_dev *dev)
+{
+	pci_disable_msi(dev);
+}
+
 #define PCI_VENDOR_ID_SBSMODULARIO	0x124B
 #define PCI_SUBVENDOR_ID_SBSMODULARIO	0x124B
 #define PCI_DEVICE_ID_OCTPRO		0x0001
@@ -1133,9 +1152,14 @@ pci_xr17c154_setup(struct serial_private *priv,
 #define PCI_DEVICE_ID_TITAN_800E	0xA014
 #define PCI_DEVICE_ID_TITAN_200EI	0xA016
 #define PCI_DEVICE_ID_TITAN_200EISI	0xA017
+#define PCI_DEVICE_ID_TITAN_400V3	0xA310
+#define PCI_DEVICE_ID_TITAN_410V3	0xA312
+#define PCI_DEVICE_ID_TITAN_800V3	0xA314
+#define PCI_DEVICE_ID_TITAN_800V3B	0xA315
 #define PCI_DEVICE_ID_OXSEMI_16PCI958	0x9538
 #define PCIE_DEVICE_ID_NEO_2_OX_IBM	0x00F6
 #define PCI_DEVICE_ID_PLX_CRONYX_OMEGA	0xc001
+#define PCI_DEVICE_ID_INTEL_PATSBURG_KT 0x1d3d
 
 /* Unknown vendors/cards - this should not be in linux/pci_ids.h */
 #define PCI_SUBDEVICE_ID_UNKNOWN_0x1584	0x1584
@@ -1220,6 +1244,15 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.subdevice	= PCI_ANY_ID,
 		.setup		= ce4100_serial_setup,
 	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_PATSBURG_KT,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= try_enable_msi,
+		.setup		= kt_serial_setup,
+		.exit		= disable_msi,
+	},
 	/*
 	 * ITE
 	 */
@@ -3414,6 +3447,18 @@ static struct pci_device_id serial_pci_tbl[] = {
 	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200EISI,
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 		pbn_oxsemi_2_4000000 },