From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frans Klaver Subject: [PATCH 2/4] tty: omap-serial: prevent division by zero Date: Mon, 15 Sep 2014 16:00:08 +0200 Message-ID: <1410789610-23059-3-git-send-email-frans.klaver@xsens.com> References: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Tony Lindgren Cc: Mark Rutland , Frans Klaver , Alexey Pelykh , Pawel Moll , Ian Campbell , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Felipe Balbi , devicetree@vger.kernel.org, Rob Herring , linux-serial@vger.kernel.org, Kumar Gala , linux-omap@vger.kernel.org, Jiri Slaby , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.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..7d3f557 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 - (port->uartclk / (mode * n)); if (abs_diff < 0) abs_diff = -abs_diff; -- 2.1.0