Merge tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver patchset for 3.18-rc1.

  Lots of little things in here, some good work from Peter Hurley on the
  tty core, and in lots of drivers.  There are also lots of other driver
  updates in here as well, full details in the changelogs.

  All have been in the linux-next tree for a while"

* tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (99 commits)
  Revert "serial/core: Initialize the console pm state"
  tty: serial: 8250: use 32bit variable for rpm_tx_active
  tty: serial: msm: Add earlycon support
  serial/core: Initialize the console pm state
  serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)
  serial: of-serial: add PM suspend/resume support
  m68k: AMIGA_BUILTIN_SERIAL should depend on TTY
  asm/uapi: Add definition of TIOC[SG]RS485
  tty/metag_da: Add console_poll module parameter
  serial: 8250_pci: remove rts_n override from Baytrail quirk
  serial: cadence: Add generic earlycon support
  serial: imx: change the wait even to interruptiable
  serial: imx: terminate the RX DMA when the UART is suspending
  serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
  serial: 8250: Add Quark X1000 to 8250_pci.c
  tty: omap-serial: pull out calculation from baud_is_mode16
  tty: omap-serial: fix division by zero
  xen_hvc: no reason to write the type key on xenstore
  tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
  tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
  ...

1 files changed, 14 insertions, 35 deletions

diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 6fd60fece6b4..62380ccf70fb 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -402,7 +402,7 @@ void tty_termios_encode_baud_rate(struct ktermios *termios,
 
 #ifdef BOTHER
 	/* If the user asked for a precise weird speed give a precise weird
-	   answer. If they asked for a Bfoo speed they many have problems
+	   answer. If they asked for a Bfoo speed they may have problems
 	   digesting non-exact replies so fuzz a bit */
 
 	if ((termios->c_cflag & CBAUD) == BOTHER)
@@ -912,35 +912,6 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
 #endif
 
 /**
- *	send_prio_char		-	send priority character
- *
- *	Send a high priority character to the tty even if stopped
- *
- *	Locking: none for xchar method, write ordering for write method.
- */
-
-static int send_prio_char(struct tty_struct *tty, char ch)
-{
-	int	was_stopped = tty->stopped;
-
-	if (tty->ops->send_xchar) {
-		tty->ops->send_xchar(tty, ch);
-		return 0;
-	}
-
-	if (tty_write_lock(tty, 0) < 0)
-		return -ERESTARTSYS;
-
-	if (was_stopped)
-		start_tty(tty);
-	tty->ops->write(tty, &ch, 1);
-	if (was_stopped)
-		stop_tty(tty);
-	tty_write_unlock(tty);
-	return 0;
-}
-
-/**
  *	tty_change_softcar	-	carrier change ioctl helper
  *	@tty: tty to update
  *	@arg: enable/disable CLOCAL
@@ -1177,29 +1148,37 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 			return retval;
 		switch (arg) {
 		case TCOOFF:
+			spin_lock_irq(&tty->flow_lock);
 			if (!tty->flow_stopped) {
 				tty->flow_stopped = 1;
-				stop_tty(tty);
+				__stop_tty(tty);
 			}
+			spin_unlock_irq(&tty->flow_lock);
 			break;
 		case TCOON:
+			spin_lock_irq(&tty->flow_lock);
 			if (tty->flow_stopped) {
 				tty->flow_stopped = 0;
-				start_tty(tty);
+				__start_tty(tty);
 			}
+			spin_unlock_irq(&tty->flow_lock);
 			break;
 		case TCIOFF:
+			down_read(&tty->termios_rwsem);
 			if (STOP_CHAR(tty) != __DISABLED_CHAR)
-				return send_prio_char(tty, STOP_CHAR(tty));
+				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)
-				return send_prio_char(tty, START_CHAR(tty));
+				retval = tty_send_xchar(tty, START_CHAR(tty));
+			up_read(&tty->termios_rwsem);
 			break;
 		default:
 			return -EINVAL;
 		}
-		return 0;
+		return retval;
 	case TCFLSH:
 		retval = tty_check_change(tty);
 		if (retval)