Merge tag 'tty-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big tty/serial driver update for 4.14-rc1.

  Well, not all that big, just a number of small serial driver fixes,
  and a new serial driver. Also in here are some much needed goldfish
  tty driver (emulator) fixes to try to get that codebase under control.

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

* tag 'tty-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (94 commits)
  tty: goldfish: Implement support for kernel 'earlycon' parameter
  tty: goldfish: Use streaming DMA for r/w operations on Ranchu platforms
  tty: goldfish: Refactor constants to better reflect their nature
  serial: 8250_port: Remove useless NULL checks
  earlycon: initialise baud field of earlycon device structure
  tty: hvcs: make ktermios const
  pty: show associative slave of ptmx in fdinfo
  tty: n_gsm: Add compat_ioctl
  tty: hvcs: constify vio_device_id
  tty: hvc_vio: constify vio_device_id
  tty: mips_ejtag_fdc: constify mips_cdmm_device_id
  Introduce 8250_men_mcb
  mcb: introduce mcb_get_resource()
  serial: imx: Avoid post-PIO cleanup if TX DMA is started
  tty: serial: imx: disable irq after suspend
  serial: 8250_uniphier: add suspend/resume support
  serial: 8250_uniphier: use CHAR register for canary to detect power-off
  serial: 8250_uniphier: fix serial port index in private data
  serial: 8250: of: Add new port type for MediaTek BTIF controller on MT7622/23 SoC
  dt-bindings: serial: 8250: Add MediaTek BTIF controller bindings
  ...

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 4e7a4e9dcf4d..f8eba1c5412f 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -362,6 +362,32 @@ int tty_insert_flip_string_flags(struct tty_port *port,
 EXPORT_SYMBOL(tty_insert_flip_string_flags);
 
 /**
+ *	__tty_insert_flip_char   -	Add one character to the tty buffer
+ *	@port: tty port
+ *	@ch: character
+ *	@flag: flag byte
+ *
+ *	Queue a single byte to the tty buffering, with an optional flag.
+ *	This is the slow path of tty_insert_flip_char.
+ */
+int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag)
+{
+	struct tty_buffer *tb;
+	int flags = (flag == TTY_NORMAL) ? TTYB_NORMAL : 0;
+
+	if (!__tty_buffer_request_room(port, 1, flags))
+		return 0;
+
+	tb = port->buf.tail;
+	if (~tb->flags & TTYB_NORMAL)
+		*flag_buf_ptr(tb, tb->used) = flag;
+	*char_buf_ptr(tb, tb->used++) = ch;
+
+	return 1;
+}
+EXPORT_SYMBOL(__tty_insert_flip_char);
+
+/**
  *	tty_schedule_flip	-	push characters to ldisc
  *	@port: tty port to push from
  *