[PATCH 1/3] tty: serial: Fix mediatek UART driver setting baudrate issue

From: Eddie Huang
Date: Wed Oct 22 2014 - 09:17:54 EST


In mtk8250_set_termios function, calculating quot value can not be zero,
otherwise, using DIV_ROUND_CLOSEST(port->uartclk, quot * baud) will fail due to
divisor is zero.

Signed-off-by: Eddie Huang <eddie.huang@xxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_mtk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 8f37d57..6f93123 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -74,14 +74,14 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
/* Set to next lower baudrate supported */
if ((baud == 500000) || (baud == 576000))
baud = 460800;
- quot = DIV_ROUND_CLOSEST(port->uartclk, 4 * baud);
+ quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
} else {
serial_port_out(port, UART_MTK_HIGHS, 0x3);

/* Set to highest baudrate supported */
if (baud >= 1152000)
baud = 921600;
- quot = DIV_ROUND_CLOSEST(port->uartclk, 256 * baud);
+ quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
}

/*
--
1.8.1.1.dirty

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