TTY/Serial fixes for 4.4-rc2

Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve
 some reported problems.
 
 All have been in linux-next, full details are in the shortlog below.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve
  some reported problems.

  All have been in linux-next, full details are in the shortlog below"

* tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: export fsl8250_handle_irq
  serial: 8250_mid: Add missing dependency
  tty: audit: Fix audit source
  serial: etraxfs-uart: Fix crash
  serial: fsl_lpuart: Fix earlycon support
  bcm63xx_uart: Use the device name when registering an interrupt
  tty: Fix direct use of tty buffer work
  tty: Fix tty_send_xchar() lock order inversion

drivers/tty/n_tty.c

@@ -169,7 +169,7 @@ static inline int tty_copy_to_user(struct tty_struct *tty,
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	tty_audit_add_data(tty, to, n, ldata->icanon);
+	tty_audit_add_data(tty, from, n, ldata->icanon);
 	return copy_to_user(to, from, n);
 }
 

drivers/tty/serial/8250/8250_fsl.c

@@ -60,3 +60,4 @@ int fsl8250_handle_irq(struct uart_port *port)
 	spin_unlock_irqrestore(&up->port.lock, flags);
 	return 1;
 }
+EXPORT_SYMBOL_GPL(fsl8250_handle_irq);

drivers/tty/serial/8250/Kconfig

@@ -373,6 +373,7 @@ config SERIAL_8250_MID
 	depends on SERIAL_8250 && PCI
 	select HSU_DMA if SERIAL_8250_DMA
 	select HSU_DMA_PCI if X86_INTEL_MID
+	select RATIONAL
 	help
 	  Selecting this option will enable handling of the extra features
 	  present on the UART found on Intel Medfield SOC and various other

drivers/tty/serial/Kconfig

@@ -1539,7 +1539,6 @@ config SERIAL_FSL_LPUART
 	tristate "Freescale lpuart serial port support"
 	depends on HAS_DMA
 	select SERIAL_CORE
-	select SERIAL_EARLYCON
 	help
 	  Support for the on-chip lpuart on some Freescale SOCs.
 
@@ -1547,6 +1546,7 @@ config SERIAL_FSL_LPUART_CONSOLE
 	bool "Console on Freescale lpuart serial port"
 	depends on SERIAL_FSL_LPUART=y
 	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
 	help
 	  If you have enabled the lpuart serial port on the Freescale SoCs,
 	  you can make it the console by answering Y to this option.

drivers/tty/serial/bcm63xx_uart.c

@@ -474,7 +474,7 @@ static int bcm_uart_startup(struct uart_port *port)
 
 	/* register irq and enable rx interrupts */
 	ret = request_irq(port->irq, bcm_uart_interrupt, 0,
-			  bcm_uart_type(port), port);
+			  dev_name(port->dev), port);
 	if (ret)
 		return ret;
 	bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);

drivers/tty/serial/etraxfs-uart.c

@@ -894,7 +894,7 @@ static int etraxfs_uart_probe(struct platform_device *pdev)
 	up->regi_ser = of_iomap(np, 0);
 	up->port.dev = &pdev->dev;
 
-	up->gpios = mctrl_gpio_init(&pdev->dev, 0);
+	up->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
 	if (IS_ERR(up->gpios))
 		return PTR_ERR(up->gpios);
 

drivers/tty/tty_audit.c

@@ -265,7 +265,7 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
  *
  *	Audit @data of @size from @tty, if necessary.
  */
-void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
+void tty_audit_add_data(struct tty_struct *tty, const void *data,
 			size_t size, unsigned icanon)
 {
 	struct tty_audit_buf *buf;

drivers/tty/tty_io.c

@@ -1282,18 +1282,22 @@ int tty_send_xchar(struct tty_struct *tty, char ch)
 	int	was_stopped = tty->stopped;
 
 	if (tty->ops->send_xchar) {
+		down_read(&tty->termios_rwsem);
 		tty->ops->send_xchar(tty, ch);
+		up_read(&tty->termios_rwsem);
 		return 0;
 	}
 
 	if (tty_write_lock(tty, 0) < 0)
 		return -ERESTARTSYS;
 
+	down_read(&tty->termios_rwsem);
 	if (was_stopped)
 		start_tty(tty);
 	tty->ops->write(tty, &ch, 1);
 	if (was_stopped)
 		stop_tty(tty);
+	up_read(&tty->termios_rwsem);
 	tty_write_unlock(tty);
 	return 0;
 }

drivers/tty/tty_ioctl.c

@@ -1147,16 +1147,12 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 			spin_unlock_irq(&tty->flow_lock);
 			break;
 		case TCIOFF:
-			down_read(&tty->termios_rwsem);
 			if (STOP_CHAR(tty) != __DISABLED_CHAR)
 				retval = tty_send_xchar(tty, STOP_CHAR(tty));
-			up_read(&tty->termios_rwsem);
 			break;
 		case TCION:
-			down_read(&tty->termios_rwsem);
 			if (START_CHAR(tty) != __DISABLED_CHAR)
 				retval = tty_send_xchar(tty, START_CHAR(tty));
-			up_read(&tty->termios_rwsem);
 			break;
 		default:
 			return -EINVAL;

drivers/tty/tty_ldisc.c

@@ -592,7 +592,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
 	/* Restart the work queue in case no characters kick it off. Safe if
 	   already running */
-	schedule_work(&tty->port->buf.work);
+	tty_buffer_restart_work(tty->port);
 
 	tty_unlock(tty);
 	return retval;

include/linux/tty.h

@@ -607,7 +607,7 @@ extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT
-extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
+extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
 			       size_t size, unsigned icanon);
 extern void tty_audit_exit(void);
 extern void tty_audit_fork(struct signal_struct *sig);
@@ -615,8 +615,8 @@ extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 extern void tty_audit_push(struct tty_struct *tty);
 extern int tty_audit_push_current(void);
 #else
-static inline void tty_audit_add_data(struct tty_struct *tty,
-		unsigned char *data, size_t size, unsigned icanon)
+static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
+				      size_t size, unsigned icanon)
 {
 }
 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)