From 2d8d417ba69bda317a9d3466b97e2e4dc4d6f3d5 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Wed, 30 Apr 2008 00:53:34 -0700
Subject: [PATCH] --- yaml --- r: 95180 b: refs/heads/master c:
 1c2630ccf922b7ea2c54c184243d4fb2bd2cf3c6 h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/drivers/char/tty_ioctl.c | 33 +++++++++++++++++++++++++++------
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index e3f0525ac6da..00715d6dafe9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0ee9cbb3c705903db9c258047d9ce87096e6a1a1
+refs/heads/master: 1c2630ccf922b7ea2c54c184243d4fb2bd2cf3c6
diff --git a/trunk/drivers/char/tty_ioctl.c b/trunk/drivers/char/tty_ioctl.c
index 851cfcd2702a..d769e43f73fb 100644
--- a/trunk/drivers/char/tty_ioctl.c
+++ b/trunk/drivers/char/tty_ioctl.c
@@ -755,6 +755,32 @@ static int send_prio_char(struct tty_struct *tty, char ch)
 	return 0;
 }
 
+/**
+ *	tty_change_softcar	-	carrier change ioctl helper
+ *	@tty: tty to update
+ *	@arg: enable/disable CLOCAL
+ *
+ *	Perform a change to the CLOCAL state and call into the driver
+ *	layer to make it visible. All done with the termios mutex
+ */
+
+static int tty_change_softcar(struct tty_struct *tty, int arg)
+{
+	int ret = 0;
+	int bit = arg ? CLOCAL : 0;
+	struct ktermios old = *tty->termios;
+
+	mutex_lock(&tty->termios_mutex);
+	tty->termios->c_cflag &= ~CLOCAL;
+	tty->termios->c_cflag |= bit;
+	if (tty->driver->set_termios)
+		tty->driver->set_termios(tty, &old);
+	if ((tty->termios->c_cflag & CLOCAL) != bit)
+		ret = -EINVAL;
+	mutex_unlock(&tty->termios_mutex);
+	return ret;
+}
+
 /**
  *	tty_mode_ioctl		-	mode related ioctls
  *	@tty: tty for the ioctl
@@ -865,12 +891,7 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 	case TIOCSSOFTCAR:
 		if (get_user(arg, (unsigned int __user *) arg))
 			return -EFAULT;
-		mutex_lock(&tty->termios_mutex);
-		tty->termios->c_cflag =
-			((tty->termios->c_cflag & ~CLOCAL) |
-			 (arg ? CLOCAL : 0));
-		mutex_unlock(&tty->termios_mutex);
-		return 0;
+		return tty_change_softcar(tty, arg);
 	default:
 		return -ENOIOCTLCMD;
 	}