old serial card entry I made. But I left out any REAL information that might have been helpful. So here is that data so I can search for it in the future and still not be able to find it.
Setting up a StarTech PCI1S550 Serial Card
# more /proc/pci
[garbage to ignore..... the last few lines should be similar]
Bus 0, Device 11, function 0:
Serial controller : Unknown vendor Unknown device (rev 01).
Vendor id=9710, Device id=9820
Medium devsel. Fast back-to-back capable. IRQ 11
I/O at 0xc000 [0xc001] serial port 1
I/O at 0xc400 [0xc401] serial port 2
I/O at 0xc800 [0xc801] not used
I/O at 0xd000 [0xd001] not used
I/O at 0xd400 [0xd401] not used
I/O at 0xd800 [0xd801] not used
Pay attention to the 0xc000 and 0xc400 lines. Those first two lines are the important ones. Yours won't match the numbers above.
Next, determine what ttyS numbers are already in use. You can do this by viewing the /etc/inittab file and looking for lines that start with 'S#:2345'. The ttyS numbers that get added by this serial card need to be higher than the numbers already in use. For example, if S0 and S1, are in the inittab file, then we'll be creating ttyS2 and ttyS3 in the examples below.
Add these lines to /etc/rc.d/rc.local:
setserial /dev/ttyS1 port 0xc000 uart 16550 irq 11 baud_base 115200
setserial /dev/ttyS2 port 0xc400 uart 16550 irq 11 baud_base 115200
Add a couple of lines to /etc/inittab:
S1:2345:off:/sbin/getty ttyS1 DT19200 ansi
S2:2345:off:/sbin/getty ttyS2 DT19200 ansi
Reboot. The serial port(s) should work fine now.