Skip to contentSkip to conversation

Patch "serial: 8250_pci: fix divide error bug if baud rate is 0" has been added to the 4.5-stable tree

PATCH [email protected] 1 participant 1 message May 30, 2016

Subsystems (2)
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

serial: 8250_pci: fix divide error bug if baud rate is 0

to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     serial-8250_pci-fix-divide-error-bug-if-baud-rate-is-0.patch

and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?David=20M=C3=BCller?= <[email protected]>
Date: Wed, 27 Apr 2016 11:58:32 +0200
Subject: serial: 8250_pci: fix divide error bug if baud rate is 0
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: David Müller <[email protected]>

commit 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef upstream.

Since commit 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula"), the 8250 driver crashes in the byt_set_termios() function with a divide error. This is caused by the fact that a baud rate of 0 (B0) is not handled properly. Fix it by falling back to B9600 in this case.

Fixes 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula")
---
 drivers/tty/serial/8250/8250_pci.c |    3 +++
 1 file changed, 3 insertions(+)
drivers/tty/serial/8250/8250_pci.c +3 -0
@@ -1401,6 +1401,9 @@ byt_set_termios(struct uart_port *p, str
 	unsigned long m, n;
 	u32 reg;
 
+	/* Gracefully handle the B0 case: fall back to B9600 */
+	fuart = fuart ? fuart : 9600 * 16;
+
 	/* Get Fuart closer to Fref */
 	fuart *= rounddown_pow_of_two(fref / fuart);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.5/serial-8250_pci-fix-divide-error-bug-if-baud-rate-is-0.patch