[ltp] How can I know the serial on port replicator works ?

[Bob Alexander]

I am losing my last two hairs trying to get gpsd working with a cable 
going from my old Garmin etrex to a serial connector. As my T40 does not 
have one I am using the serial connector which comes out behind the port 
replicator.

I am getting no signal apparently and dunno if the device is alive 
and/or what.

Using a 2.6.11.4 kernel with the following:

bob@t40:/usr/src/linux-2.6.11.4$ grep SERIAL .config |grep -v ^#
CONFIG_SERIAL_8250=m
CONFIG_SERIAL_8250_CS=m
CONFIG_SERIAL_8250_ACPI=y
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_CORE=m
CONFIG_USB_SERIAL=m
CONFIG_USB_SERIAL_VISOR=m

In dmesg I see several
ttyS0: LSR safety check engaged!

but I am not quite sure /dev/ttyS0 is that serial port on the back of 
the replicator.

Any help ?

TIA,
Bob