/var/log/messages
ugen0: I/O Data product 0x0911, rev 1.00/1.00, addr 2
uplcom0: I/O Data product 0x0911, rev 1.00/1.00, addr 2
uplcom0: Could not find interrupt in
device_probe_and_attach: uplcom0 attach returned 6

$ usbdevs -v
Controller /dev/usb0:
addr 1: self powered, config 1, UHCI root hub(0x0000), VIA(0x0000), rev 1.00
port 1 addr 2: power 100 mA, config 1, product 0x0911(0x0911), I/O Data(0x04bb), rev 1.00
port 2 powered