Thank to "cs_posting", Mil Wilson, and all the other respondents, I have gotten my Linux machine talking to my Luminary LM3S811 evaluation board.
The board uses an FTDI FT2232D chip in a design that is advertised as being compliant to the OpenOCD design, but which uses a unique product ID. Luminary provides Windows device drivers, but no Linux support.
It turns out that I had to edit the FTDI device driver and build my own module. I ended up building an entirely new kernel, because I didn't have time to figure out how to rebuild just one module -- that's OK, because it works and I can meet my obligations for the next few days without having to use my cranky old Windows laptop for presentations. Later on I can learn how to do it 'right' (and maybe have a kernel that'll let me talk FTDI and wireless at the same time).
The specific solution is to go into the ftdi_sio.c file, and add a line to the definition for the "id_table_combined". I put it right below the one that specifies the Olimex part, so the two lines read:
{ USB_DEVICE(OLIMEX_VID, OLIMEX_ARM_USB_OCD_PID), .driver_info = (kernel_ulong_t)&ftdi_olimex_quirk }, { USB_DEVICE(FTDI_VID, LUMINARY_LM3S811_PID), .driver_info = (kernel_ulong_t)&ftdi_olimex_quirk },
(note that I had to go into ftdi_sio.h and define LUMINARY_SM3S811_PID as
0xbcd9).Thanks again to all.