[CentOS] Serial port driver on CentOS 6

Thu Jan 5 22:10:13 UTC 2012
Alfred von Campe <alfred at von-campe.com>

I installed CentOS 6 on a Dell Optiplex 790 with a StarTech.com dual serial
port card, and the serial ports aren't being recognized.  According to dmesg,
only the built-in serial port is being recognized:

# dmesg | fgrep ttyS
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:08: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

And lspci -v doesn't show that any drivers are loaded for it:

# lspci -v
[snip]
03:00.0 Serial controller: NetMos Technology PCIe 9922 Multi-I/O Controller (prog-if 02 [16550])
        Subsystem: Device a000:1000
        Flags: fast devsel, IRQ 16
        I/O ports at 2010 [size=8]
        Memory at e1a30000 (32-bit, non-prefetchable) [size=4K]
        Memory at e1a20000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [50] MSI: Enable- Count=1/8 Maskable- 64bit+
        Capabilities: [78] Power Management version 3
        Capabilities: [80] Express Legacy Endpoint, MSI 00
        Capabilities: [100] Virtual Channel <?>
        Capabilities: [800] Advanced Error Reporting

03:00.1 Serial controller: NetMos Technology PCIe 9922 Multi-I/O Controller (prog-if 02 [16550])
        Subsystem: Device a000:1000
        Flags: fast devsel, IRQ 17
        I/O ports at 2000 [size=8]
        Memory at e1a10000 (32-bit, non-prefetchable) [size=4K]
        Memory at e1a00000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [50] MSI: Enable- Count=1/8 Maskable- 64bit+
        Capabilities: [78] Power Management version 3
        Capabilities: [80] Express Legacy Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting

What do I need to do to get these serial ports recognized?  On some other
CentOS 6 systems with StarTech.com serial cards they were automatically
recognized (different hardware and not PCIe based).

Thanks,
Alfred