From mboxrd@z Thu Jan 1 00:00:00 1970 From: frans.klaver@xsens.com (Frans Klaver) Date: Tue, 19 Aug 2014 14:14:46 +0200 Subject: [PATCH 2/4] tty: omap-serial: prevent division by zero In-Reply-To: <1408450488-4083-1-git-send-email-frans.klaver@xsens.com> References: <1406645577-18620-1-git-send-email-frans.klaver@xsens.com> <1408450488-4083-1-git-send-email-frans.klaver@xsens.com> Message-ID: <1408450488-4083-3-git-send-email-frans.klaver@xsens.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If the chosen baud rate is large enough (e.g. 3.5 megabaud), the calculated n values in calculate_baud_abs_diff may become 0. This causes a division by zero when calculating the difference between calculated and desired baud rates. To prevent this, cap n on 1. Signed-off-by: Frans Klaver --- drivers/tty/serial/omap-serial.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index ae935ce..14a0167 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -246,8 +246,12 @@ static inline int calculate_baud_abs_diff(struct uart_port *port, unsigned int baud, unsigned int mode) { unsigned int n = port->uartclk / (mode * baud); - int abs_diff = baud - (port->uartclk / (mode * n)); + int abs_diff; + if (n == 0) + n = 1; + + abs_diff = baud - (uartclk / (mode * n)); if (abs_diff < 0) abs_diff = -abs_diff; -- 1.9.3