Fix a division-by-zero in set_termios when debugging is enabled and a
high-enough speed has been requested so that the divisor value becomes
zero.

Instead of just fixing the offending debug statement, cap the baud rate
at the base as a zero divisor value also appears to crash the firmware.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <sta...@vger.kernel.org>     # 2.6.12
Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 drivers/usb/serial/io_ti.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 87798e625d6c..6cefb9cb133d 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -2336,8 +2336,11 @@ static void change_port_settings(struct tty_struct *tty,
        if (!baud) {
                /* pick a default, any default... */
                baud = 9600;
-       } else
+       } else {
+               /* Avoid a zero divisor. */
+               baud = min(baud, 461550);
                tty_encode_baud_rate(tty, baud, baud);
+       }
 
        edge_port->baud_rate = baud;
        config->wBaudRate = (__u16)((461550L + baud/2) / baud);
-- 
2.13.0

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