diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 37c46c65a65f..bb14bd4f6e55 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -876,13 +876,13 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
 	return i;
 }
 
-static void tty_write_unlock(struct tty_struct *tty)
+void tty_write_unlock(struct tty_struct *tty)
 {
 	mutex_unlock(&tty->atomic_write_lock);
 	wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
 }
 
-static int tty_write_lock(struct tty_struct *tty, int ndelay)
+int tty_write_lock(struct tty_struct *tty, int ndelay)
 {
 	if (!mutex_trylock(&tty->atomic_write_lock)) {
 		if (ndelay)
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 9245fffdbceb..5d833f0b412d 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -397,22 +397,43 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
 	tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
 	tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
 
-	ld = tty_ldisc_ref(tty);
+	if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) {
+retry_write_wait:
+		retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty));
+		if (retval < 0)
+			return retval;
 
-	if (ld != NULL) {
-		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
-			ld->ops->flush_buffer(tty);
-		tty_ldisc_deref(ld);
+		if (tty_write_lock(tty, 0) < 0)
+			goto retry_write_wait;
+
+		/* Racing writer? */
+		if (tty_chars_in_buffer(tty)) {
+			tty_write_unlock(tty);
+			goto retry_write_wait;
+		}
+
+		ld = tty_ldisc_ref(tty);
+		if (ld != NULL) {
+			if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+				ld->ops->flush_buffer(tty);
+			tty_ldisc_deref(ld);
+		}
+
+		if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) {
+			tty->ops->wait_until_sent(tty, 0);
+			if (signal_pending(current)) {
+				tty_write_unlock(tty);
+				return -ERESTARTSYS;
+			}
+		}
+
+		tty_set_termios(tty, &tmp_termios);
+
+		tty_write_unlock(tty);
+	} else {
+		tty_set_termios(tty, &tmp_termios);
 	}
 
-	if (opt & TERMIOS_WAIT) {
-		tty_wait_until_sent(tty, 0);
-		if (signal_pending(current))
-			return -ERESTARTSYS;
-	}
-
-	tty_set_termios(tty, &tmp_termios);
-
 	/* FIXME: Arguably if tmp_termios == tty->termios AND the
 	   actual requested termios was not tmp_termios then we may
 	   want to return an error as no user requested change has
diff --git a/include/linux/tty.h b/include/linux/tty.h
index eb33d948788c..8be25caa97f6 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -480,6 +480,8 @@ extern void __stop_tty(struct tty_struct *tty);
 extern void stop_tty(struct tty_struct *tty);
 extern void __start_tty(struct tty_struct *tty);
 extern void start_tty(struct tty_struct *tty);
+void tty_write_unlock(struct tty_struct *tty);
+int tty_write_lock(struct tty_struct *tty, int ndelay);
 extern int tty_register_driver(struct tty_driver *driver);
 extern int tty_unregister_driver(struct tty_driver *driver);
 extern struct device *tty_register_device(struct tty_driver *driver,