5.1-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 2.6.25.8 / fix-tty-speed-handling-on-8250.patch

From e991a2bd4fa0b2f475b67dfe8f33e8ecbdcbb40b Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Mon, 28 Apr 2008 02:14:06 -0700
Subject: Fix tty speed handling on 8250

From: Alan Cox <alan@lxorguk.ukuu.org.uk>

commit e991a2bd4fa0b2f475b67dfe8f33e8ecbdcbb40b upstream.

We try and write the correct speed back but the serial midlayer already
mangles the speed on us and that means if we request B0 we report back B9600
when we should not.  For now we'll hack around this in the drivers and serial
code, pending a better long term solution.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/serial/8250.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2174,7 +2174,9 @@ serial8250_set_termios(struct uart_port 
 	}
 	serial8250_set_mctrl(&up->port, up->port.mctrl);
 	spin_unlock_irqrestore(&up->port.lock, flags);
-	tty_termios_encode_baud_rate(termios, baud, baud);
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
 }
 
 static void