Problem using UART port with serial device

Hi,

My configuration:

-Altera cycloneV socDevKit

-Linux kernel : 3.9.0 and debian filesystem from this rocketboards project : http://www.rocketboards.org/foswiki/projects/debian

I'm trying to communicate with a serial GPS module (4800 8N1) plugged on the UART mini USB port. But I can't read data from the device.

It works fine when I use a PC with a terminal. I even disabled the login prompt in /etc/inittab to directly read data send from the device but nothing happend.

Anyone have solution ?

Maybe a driver problem or tty settings ?

Use HPS USB port could be better ?

Thanks.