Merge tag 'tty-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here's the big tty/serial driver pull request for 4.6-rc1.

  Lots of changes in here, Peter has been on a tear again, with lots of
  refactoring and bugs fixes, many thanks to the great work he has been
  doing.  Lots of driver updates and fixes as well, full details in the
  shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'tty-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (220 commits)
  serial: 8250: describe CONFIG_SERIAL_8250_RSA
  serial: samsung: optimize UART rx fifo access routine
  serial: pl011: add mark/space parity support
  serial: sa1100: make sa1100_register_uart_fns a function
  tty: serial: 8250: add MOXA Smartio MUE boards support
  serial: 8250: convert drivers to use up_to_u8250p()
  serial: 8250/mediatek: fix building with SERIAL_8250=m
  serial: 8250/ingenic: fix building with SERIAL_8250=m
  serial: 8250/uniphier: fix modular build
  Revert "drivers/tty/serial: make 8250/8250_ingenic.c explicitly non-modular"
  Revert "drivers/tty/serial: make 8250/8250_mtk.c explicitly non-modular"
  serial: mvebu-uart: initial support for Armada-3700 serial port
  serial: mctrl_gpio: Add missing module license
  serial: ifx6x60: avoid uninitialized variable use
  tty/serial: at91: fix bad offset for UART timeout register
  tty/serial: at91: restore dynamic driver binding
  serial: 8250: Add hardware dependency to RT288X option
  TTY, devpts: document pty count limiting
  tty: goldfish: support platform_device with id -1
  drivers: tty: goldfish: Add device tree bindings
  ...

1 files changed, 28 insertions, 11 deletions

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 3cd31e0d4bd9..a946e49a2626 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -435,25 +435,42 @@ int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars,
 }
 EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
 
+/**
+ *	tty_ldisc_receive_buf		-	forward data to line discipline
+ *	@ld:	line discipline to process input
+ *	@p:	char buffer
+ *	@f:	TTY_* flags buffer
+ *	@count:	number of bytes to process
+ *
+ *	Callers other than flush_to_ldisc() need to exclude the kworker
+ *	from concurrent use of the line discipline, see paste_selection().
+ *
+ *	Returns the number of bytes not processed
+ */
+int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
+			  char *f, int count)
+{
+	if (ld->ops->receive_buf2)
+		count = ld->ops->receive_buf2(ld->tty, p, f, count);
+	else {
+		count = min_t(int, count, ld->tty->receive_room);
+		if (count && ld->ops->receive_buf)
+			ld->ops->receive_buf(ld->tty, p, f, count);
+	}
+	return count;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_receive_buf);
 
 static int
-receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count)
+receive_buf(struct tty_ldisc *ld, struct tty_buffer *head, int count)
 {
-	struct tty_ldisc *disc = tty->ldisc;
 	unsigned char *p = char_buf_ptr(head, head->read);
 	char	      *f = NULL;
 
 	if (~head->flags & TTYB_NORMAL)
 		f = flag_buf_ptr(head, head->read);
 
-	if (disc->ops->receive_buf2)
-		count = disc->ops->receive_buf2(tty, p, f, count);
-	else {
-		count = min_t(int, count, tty->receive_room);
-		if (count && disc->ops->receive_buf)
-			disc->ops->receive_buf(tty, p, f, count);
-	}
-	return count;
+	return tty_ldisc_receive_buf(ld, p, f, count);
 }
 
 /**
@@ -514,7 +531,7 @@ static void flush_to_ldisc(struct work_struct *work)
 			continue;
 		}
 
-		count = receive_buf(tty, head, count);
+		count = receive_buf(disc, head, count);
 		if (!count)
 			break;
 		head->read += count;