From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:50055 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161112AbcFCVh4 (ORCPT ); Fri, 3 Jun 2016 17:37:56 -0400 From: Sasha Levin To: stable@vger.kernel.org, stable-commits@vger.kernel.org Cc: =?UTF-8?q?David=20M=C3=BCller?= , Greg Kroah-Hartman , Sasha Levin Subject: [added to the 4.1 stable tree] serial: 8250_pci: fix divide error bug if baud rate is 0 Date: Fri, 3 Jun 2016 17:35:28 -0400 Message-Id: <1464989831-16666-33-git-send-email-sasha.levin@oracle.com> In-Reply-To: <1464989831-16666-1-git-send-email-sasha.levin@oracle.com> References: <1464989831-16666-1-git-send-email-sasha.levin@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: From: David Müller This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef ] 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. Signed-off-by: David Müller Fixes: 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula") Cc: stable@vger.kernel.org Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index b82b2a0..a78a62b 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1402,6 +1402,9 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios, 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); -- 2.5.0