serial core fixes

index 8572f2a..5b82d7a 100644
@@ -1674,6 +1674,7 @@ static void pl011_shutdown(struct uart_port *port)
 			plat->exit();
 	}
 
+	pl011_dma_flush_buffer(port);
 }
 
 static void

index d7d4584..8b13d4d 100644
@@ -1801,6 +1801,20 @@ free_irq:
 }
 
 /*
+ * Flush any TX data submitted for DMA. Called when the TX circular
+ * buffer is reset.
+ */
+static void atmel_flush_buffer(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (atmel_use_pdc_tx(port)) {
+		UART_PUT_TCR(port, 0);
+		atmel_port->pdc_tx.ofs = 0;
+	}
+}
+
+/*
  * Disable the port
  */
 static void atmel_shutdown(struct uart_port *port)

@@ -1851,20 +1865,8 @@ static void atmel_shutdown(struct uart_port *port)
 	atmel_free_gpio_irq(port);
 
 	atmel_port->ms_irq_enabled = false;
-}
 
-/*
- * Flush any TX data submitted for DMA. Called when the TX circular
- * buffer is reset.
- */
-static void atmel_flush_buffer(struct uart_port *port)
-{
-	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
-
-	if (atmel_use_pdc_tx(port)) {
-		UART_PUT_TCR(port, 0);
-		atmel_port->pdc_tx.ofs = 0;
-	}
+	atmel_flush_buffer(port);
 }
 
 /*

index 53d7c31..78a5cf6 100644
@@ -1034,6 +1034,20 @@ fail_rx_dma:
 	return ret;
 }
 
+/*
+ * Flush any TX data submitted for DMA and PIO. Called when the
+ * TX circular buffer is reset.
+ */
+static void tegra_uart_flush_buffer(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+
+	tup->tx_bytes = 0;
+	if (tup->tx_dma_chan)
+		dmaengine_terminate_all(tup->tx_dma_chan);
+	return;
+}
+
 static void tegra_uart_shutdown(struct uart_port *u)
 {
 	struct tegra_uart_port *tup = to_tegra_uport(u);

@@ -1046,6 +1060,8 @@ static void tegra_uart_shutdown(struct uart_port *u)
 	tegra_uart_dma_channel_free(tup, true);
 	tegra_uart_dma_channel_free(tup, false);
 	free_irq(u->irq, tup);
+
+	tegra_uart_flush_buffer(u);
 }
 
 static void tegra_uart_enable_ms(struct uart_port *u)

@@ -1174,20 +1190,6 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	return;
 }
 
-/*
- * Flush any TX data submitted for DMA and PIO. Called when the
- * TX circular buffer is reset.
- */
-static void tegra_uart_flush_buffer(struct uart_port *u)
-{
-	struct tegra_uart_port *tup = to_tegra_uport(u);
-
-	tup->tx_bytes = 0;
-	if (tup->tx_dma_chan)
-		dmaengine_terminate_all(tup->tx_dma_chan);
-	return;
-}
-
 static const char *tegra_uart_type(struct uart_port *u)
 {
 	return TEGRA_UART_TYPE;

index 221ca6f..ce0e762 100644
@@ -1360,7 +1360,6 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 
 	mutex_lock(&port->mutex);
 	uart_shutdown(tty, state);
-	uart_flush_buffer(tty);
 
 	tty_ldisc_flush(tty);
 

index 0d11d50..e9e2523 100644
@@ -273,6 +273,8 @@ static void timbuart_shutdown(struct uart_port *port)
 	dev_dbg(port->dev, "%s\n", __func__);
 	free_irq(port->irq, uart);
 	iowrite32(0, port->membase + TIMBUART_IER);
+
+	timbuart_flush_buffer(port);
 }
 
 static int get_bindex(int baud)

index ce0e762..6203c6c 100644
@@ -1360,9 +1360,6 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 
 	mutex_lock(&port->mutex);
 	uart_shutdown(tty, state);
-
-	tty_ldisc_flush(tty);
-
 	tty_port_tty_set(port, NULL);
 	tty->closing = 0;
 	spin_lock_irqsave(&port->lock, flags);

@@ -1389,6 +1386,8 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	wake_up_interruptible(&port->close_wait);
 
 	mutex_unlock(&port->mutex);
+
+	tty_ldisc_flush(tty);
 }
 
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)

index 6203c6c..6ebe78c 100644
@@ -436,7 +436,7 @@ uart_get_divisor(struct uart_port *port, unsigned int baud)
 
 EXPORT_SYMBOL(uart_get_divisor);
 
-/* FIXME: Consistent locking policy */
+/* Caller holds port mutex */
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios)
 {

@@ -1172,11 +1172,15 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd,
 		break;
 
 	case TIOCSSERIAL:
+		down_write(&tty->termios_rwsem);
 		ret = uart_set_info_user(tty, state, uarg);
+		up_write(&tty->termios_rwsem);
 		break;
 
 	case TIOCSERCONFIG:
+		down_write(&tty->termios_rwsem);
 		ret = uart_do_autoconfig(tty, state);
+		up_write(&tty->termios_rwsem);
 		break;
 
 	case TIOCSERGWILD: /* obsolete */

@@ -1277,7 +1281,9 @@ static void uart_set_termios(struct tty_struct *tty,
 		return;
 	}
 
+	mutex_lock(&state->port.mutex);
 	uart_change_speed(tty, state, old_termios);
+	mutex_unlock(&state->port.mutex);
 	/* reload cflag from termios; port driver may have overriden flags */
 	cflag = tty->termios.c_cflag;
 

index bb828a5..ab7180e 100644
@@ -156,21 +156,33 @@ struct uart_port {
 	/* flags must be updated while holding port mutex */
 	upf_t			flags;
 
-#define UPF_FOURPORT		((__force upf_t) (1 << 1))
-#define UPF_SAK			((__force upf_t) (1 << 2))
-#define UPF_SPD_MASK		((__force upf_t) (0x1030))
-#define UPF_SPD_HI		((__force upf_t) (0x0010))
-#define UPF_SPD_VHI		((__force upf_t) (0x0020))
-#define UPF_SPD_CUST		((__force upf_t) (0x0030))
-#define UPF_SPD_SHI		((__force upf_t) (0x1000))
-#define UPF_SPD_WARP		((__force upf_t) (0x1010))
-#define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
-#define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
-#define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
-#define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
-#define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
+	/*
+	 * These flags must be equivalent to the flags defined in
+	 * include/uapi/linux/tty_flags.h which are the userspace definitions
+	 * assigned from the serial_struct flags in uart_set_info()
+	 * [for bit definitions in the UPF_CHANGE_MASK]
+	 *
+	 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
+	 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
+	 * The remaining bits are serial-core specific and not modifiable by
+	 * userspace.
+	 */
+#define UPF_FOURPORT		((__force upf_t) ASYNC_FOURPORT       /* 1  */ )
+#define UPF_SAK			((__force upf_t) ASYNC_SAK            /* 2  */ )
+#define UPF_SPD_HI		((__force upf_t) ASYNC_SPD_HI         /* 4  */ )
+#define UPF_SPD_VHI		((__force upf_t) ASYNC_SPD_VHI        /* 5  */ )
+#define UPF_SPD_CUST		((__force upf_t) ASYNC_SPD_CUST   /* 0x0030 */ )
+#define UPF_SPD_WARP		((__force upf_t) ASYNC_SPD_WARP   /* 0x1010 */ )
+#define UPF_SPD_MASK		((__force upf_t) ASYNC_SPD_MASK   /* 0x1030 */ )
+#define UPF_SKIP_TEST		((__force upf_t) ASYNC_SKIP_TEST      /* 6  */ )
+#define UPF_AUTO_IRQ		((__force upf_t) ASYNC_AUTO_IRQ       /* 7  */ )
+#define UPF_HARDPPS_CD		((__force upf_t) ASYNC_HARDPPS_CD     /* 11 */ )
+#define UPF_SPD_SHI		((__force upf_t) ASYNC_SPD_SHI        /* 12 */ )
+#define UPF_LOW_LATENCY		((__force upf_t) ASYNC_LOW_LATENCY    /* 13 */ )
+#define UPF_BUGGY_UART		((__force upf_t) ASYNC_BUGGY_UART     /* 14 */ )
 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
-#define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
+#define UPF_MAGIC_MULTIPLIER	((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
+
 /* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 #define UPF_HARD_FLOW		((__force upf_t) (1 << 21))
 /* Port has hardware-assisted s/w flow control */

@@ -186,9 +198,14 @@ struct uart_port {
 #define UPF_DEAD		((__force upf_t) (1 << 30))
 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
 
-#define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
+#define __UPF_CHANGE_MASK	0x17fff
+#define UPF_CHANGE_MASK		((__force upf_t) __UPF_CHANGE_MASK)
 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 
+#if __UPF_CHANGE_MASK > ASYNC_FLAGS
+#error Change mask not equivalent to userspace-visible bit defines
+#endif
+
 	/* status must be updated while holding port lock */
 	upstat_t		status;
 

index eefcb48..7b516f7 100644
@@ -6,6 +6,8 @@
  * shared by the tty_port flags structures.
  *
  * Define ASYNCB_* for convenient use with {test,set,clear}_bit.
+ *
+ * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable
  */
 #define ASYNCB_HUP_NOTIFY	 0 /* Notify getty on hangups and closes
 				    * on the callout port */

@@ -26,7 +28,8 @@
 #define ASYNCB_BUGGY_UART	14 /* This is a buggy UART, skip some safety
 				    * checks.  Note: can be dangerous! */
 #define ASYNCB_AUTOPROBE	15 /* Port was autoprobed by PCI or PNP code */
-#define ASYNCB_LAST_USER	15
+#define ASYNCB_MAGIC_MULTIPLIER	16 /* Use special CLK or divisor */
+#define ASYNCB_LAST_USER	16
 
 /* Internal flags used only by kernel */
 #define ASYNCB_INITIALIZED	31 /* Serial port was initialized */

@@ -57,6 +60,7 @@
 #define ASYNC_LOW_LATENCY	(1U << ASYNCB_LOW_LATENCY)
 #define ASYNC_BUGGY_UART	(1U << ASYNCB_BUGGY_UART)
 #define ASYNC_AUTOPROBE		(1U << ASYNCB_AUTOPROBE)
+#define ASYNC_MAGIC_MULTIPLIER	(1U << ASYNCB_MAGIC_MULTIPLIER)
 
 #define ASYNC_FLAGS		((1U << (ASYNCB_LAST_USER + 1)) - 1)
 #define ASYNC_USR_MASK		(ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \

index 7b516f7..4e021e3 100644
@@ -8,6 +8,7 @@
  * Define ASYNCB_* for convenient use with {test,set,clear}_bit.
  *
  * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable
+ * [x] in the bit comments indicates the flag is defunct and no longer used.
  */
 #define ASYNCB_HUP_NOTIFY	 0 /* Notify getty on hangups and closes
 				    * on the callout port */

@@ -19,15 +20,15 @@
 #define ASYNCB_SKIP_TEST	 6 /* Skip UART test during autoconfiguration */
 #define ASYNCB_AUTO_IRQ		 7 /* Do automatic IRQ during
 				    * autoconfiguration */
-#define ASYNCB_SESSION_LOCKOUT	 8 /* Lock out cua opens based on session */
-#define ASYNCB_PGRP_LOCKOUT	 9 /* Lock out cua opens based on pgrp */
-#define ASYNCB_CALLOUT_NOHUP	10 /* Don't do hangups for cua device */
+#define ASYNCB_SESSION_LOCKOUT	 8 /* [x] Lock out cua opens based on session */
+#define ASYNCB_PGRP_LOCKOUT	 9 /* [x] Lock out cua opens based on pgrp */
+#define ASYNCB_CALLOUT_NOHUP	10 /* [x] Don't do hangups for cua device */
 #define ASYNCB_HARDPPS_CD	11 /* Call hardpps when CD goes high  */
 #define ASYNCB_SPD_SHI		12 /* Use 230400 instead of 38400 bps */
 #define ASYNCB_LOW_LATENCY	13 /* Request low latency behaviour */
 #define ASYNCB_BUGGY_UART	14 /* This is a buggy UART, skip some safety
 				    * checks.  Note: can be dangerous! */
-#define ASYNCB_AUTOPROBE	15 /* Port was autoprobed by PCI or PNP code */
+#define ASYNCB_AUTOPROBE	15 /* [x] Port was autoprobed by PCI/PNP code */
 #define ASYNCB_MAGIC_MULTIPLIER	16 /* Use special CLK or divisor */
 #define ASYNCB_LAST_USER	16
 

index 8fbad3410c75..46b2b3b3555c 100644
@@ -2830,6 +2830,22 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			break;
 		}
 		break;
+	case TIOCSSERIAL:
+		{
+			static DEFINE_RATELIMIT_STATE(depr_flags,
+					DEFAULT_RATELIMIT_INTERVAL,
+					DEFAULT_RATELIMIT_BURST);
+			int flags;
+			char comm[TASK_COMM_LEN];
+			if (!get_user(flags, (int __user *)arg) &&
+					(flags & ASYNC_DEPRECATED) &&
+					__ratelimit(&depr_flags)) {
+				pr_warning("%s is using deprecated flags: %.8x\n",
+						get_task_comm(comm, current),
+						flags & ASYNC_DEPRECATED);
+			}
+		}
+		break;
 	}
 	if (tty->ops->ioctl) {
 		retval = (tty->ops->ioctl)(tty, cmd, arg);

index eefcb483a2c0..879b91713e7c 100644
@@ -59,6 +59,8 @@
 #define ASYNC_AUTOPROBE		(1U << ASYNCB_AUTOPROBE)
 
 #define ASYNC_FLAGS		((1U << (ASYNCB_LAST_USER + 1)) - 1)
+#define ASYNC_DEPRECATED	(ASYNC_SESSION_LOCKOUT | ASYNC_PGRP_LOCKOUT | \
+		ASYNC_CALLOUT_NOHUP | ASYNC_AUTOPROBE)
 #define ASYNC_USR_MASK		(ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \
 		ASYNC_LOW_LATENCY)
 #define ASYNC_SPD_CUST		(ASYNC_SPD_HI|ASYNC_SPD_VHI)

index 6ebe78c..be58916 100644
@@ -1373,8 +1373,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	if (port->blocked_open) {
 		spin_unlock_irqrestore(&port->lock, flags);
 		if (port->close_delay)
-			msleep_interruptible(
-					jiffies_to_msecs(port->close_delay));
+			msleep_interruptible(jiffies_to_msecs(port->close_delay));
 		spin_lock_irqsave(&port->lock, flags);
 	} else if (!uart_console(uport)) {
 		spin_unlock_irqrestore(&port->lock, flags);

index be58916..676c03a 100644
@@ -2346,8 +2346,6 @@ int uart_register_driver(struct uart_driver *drv)
 
 		tty_port_init(port);
 		port->ops = &uart_port_ops;
-		port->close_delay     = HZ / 2;	/* .5 seconds */
-		port->closing_wait    = 30 * HZ;/* 30 seconds */
 	}
 
 	retval = tty_register_driver(normal);

index 676c03a..e04ae58 100644
@@ -2594,11 +2594,12 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 		goto out;
 	}
 
+	/* Link the port to the driver state table and vice versa */
 	state->uart_port = uport;
-	state->pm_state = UART_PM_STATE_UNDEFINED;
+	uport->state = state;
 
+	state->pm_state = UART_PM_STATE_UNDEFINED;
 	uport->cons = drv->cons;
-	uport->state = state;
 
 	/*
 	 * If this port is a console, then the spinlock is already

index e04ae58..6a3571e 100644
@@ -537,9 +537,10 @@ static int uart_write(struct tty_struct *tty,
 		count -= c;
 		ret += c;
 	}
+
+	__uart_start(tty);
 	spin_unlock_irqrestore(&port->lock, flags);
 
-	uart_start(tty);
 	return ret;
 }
 

index 6a3571e..3f02c2b 100644
@@ -1337,8 +1337,16 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	struct uart_port *uport;
 	unsigned long flags;
 
-	if (!state)
+	if (!state) {
+		struct uart_driver *drv = tty->driver->driver_state;
+
+		state = drv->state + tty->index;
+		port = &state->port;
+		spin_lock_irq(&port->lock);
+		--port->count;
+		spin_unlock_irq(&port->lock);
 		return;
+	}
 
 	uport = state->uart_port;
 	port = &state->port;

@@ -1555,6 +1563,10 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 
 	pr_debug("uart_open(%d) called\n", line);
 
+	spin_lock_irq(&port->lock);
+	++port->count;
+	spin_unlock_irq(&port->lock);
+
 	/*
 	 * We take the semaphore here to guarantee that we won't be re-entered
 	 * while allocating the state structure, or while we request any IRQs

@@ -1567,17 +1579,11 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 		goto end;
 	}
 
-	port->count++;
 	if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
 		retval = -ENXIO;
-		goto err_dec_count;
+		goto err_unlock;
 	}
 
-	/*
-	 * Once we set tty->driver_data here, we are guaranteed that
-	 * uart_close() will decrement the driver module use count.
-	 * Any failures from here onwards should not touch the count.
-	 */
 	tty->driver_data = state;
 	state->uart_port->state = state;
 	state->port.low_latency =

@@ -1598,8 +1604,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 
 end:
 	return retval;
-err_dec_count:
-	port->count--;
+err_unlock:
 	mutex_unlock(&port->mutex);
 	goto end;
 }