From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: [PATCH v1 1/1] serial: 8250_mid: fix divide error bug if baud rate is 0 Date: Fri, 1 Jul 2016 17:21:49 +0300 Message-ID: <1467382909-118812-1-git-send-email-andriy.shevchenko@linux.intel.com> Return-path: Sender: stable-owner@vger.kernel.org To: Greg Kroah-Hartman , Heikki Krogerus , linux-serial@vger.kernel.org, "Mendez Salinas, Fernando" Cc: Andy Shevchenko , stable@vger.kernel.org List-Id: linux-serial@vger.kernel.org Since the commit c1a67b48f6a5 ("serial: 8250_pci: replace switch-case by formula for Intel MID"), 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. Reported-by: "Mendez Salinas, Fernando" Fixes: c1a67b48f6a5 ("serial: 8250_pci: replace switch-case by formula for Intel MID") Cc: stable@vger.kernel.org Signed-off-by: Andy Shevchenko --- drivers/tty/serial/8250/8250_mid.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c index ac37f67..44c71f4 100644 --- a/drivers/tty/serial/8250/8250_mid.c +++ b/drivers/tty/serial/8250/8250_mid.c @@ -173,6 +173,9 @@ static void mid8250_set_termios(struct uart_port *p, unsigned long w = BIT(24) - 1; unsigned long mul, div; + /* Gracefully handle the B0 case: fall back to B9600 */ + fuart = fuart ? fuart : 9600 * 16; + if (mid->board->freq < fuart) { /* Find prescaler value that satisfies Fuart < Fref */ if (mid->board->freq > baud) -- 2.8.1