From de5fd3607292f41f8bbb6198e79587f781de1211 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Mon, 28 Apr 2008 02:14:07 -0700
Subject: [PATCH] --- yaml --- r: 94089 b: refs/heads/master c:
 eb424fd21c0931e998156225f2a0910167c3e16c h: refs/heads/master i:   94087:
 d0ed07aea4deba22abd95aabcd3d76e20af4d9a3 v: v3

---
 [refs]                             |  2 +-
 trunk/drivers/serial/serial_core.c | 15 +++++++++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index c93e6ed96117..a1c30899072a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e991a2bd4fa0b2f475b67dfe8f33e8ecbdcbb40b
+refs/heads/master: eb424fd21c0931e998156225f2a0910167c3e16c
diff --git a/trunk/drivers/serial/serial_core.c b/trunk/drivers/serial/serial_core.c
index a9ca03ead3e5..977ce820ce30 100644
--- a/trunk/drivers/serial/serial_core.c
+++ b/trunk/drivers/serial/serial_core.c
@@ -329,13 +329,15 @@ EXPORT_SYMBOL(uart_update_timeout);
  *	If it's still invalid, we try 9600 baud.
  *
  *	Update the @termios structure to reflect the baud rate
- *	we're actually going to be using.
+ *	we're actually going to be using. Don't do this for the case
+ *	where B0 is requested ("hang up").
  */
 unsigned int
 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 		   struct ktermios *old, unsigned int min, unsigned int max)
 {
 	unsigned int try, baud, altbaud = 38400;
+	int hung_up = 0;
 	upf_t flags = port->flags & UPF_SPD_MASK;
 
 	if (flags == UPF_SPD_HI)
@@ -360,8 +362,10 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 		/*
 		 * Special case: B0 rate.
 		 */
-		if (baud == 0)
+		if (baud == 0) {
+			hung_up = 1;
 			baud = 9600;
+		}
 
 		if (baud >= min && baud <= max)
 			return baud;
@@ -373,7 +377,9 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 		termios->c_cflag &= ~CBAUD;
 		if (old) {
 			baud = tty_termios_baud_rate(old);
-			tty_termios_encode_baud_rate(termios, baud, baud);
+			if (!hung_up)
+				tty_termios_encode_baud_rate(termios,
+								baud, baud);
 			old = NULL;
 			continue;
 		}
@@ -382,7 +388,8 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 		 * As a last resort, if the quotient is zero,
 		 * default to 9600 bps
 		 */
-		tty_termios_encode_baud_rate(termios, 9600, 9600);
+		if (!hung_up)
+			tty_termios_encode_baud_rate(termios, 9600, 9600);
 	}
 
 	return 0;