adding quirks to umass(4)

[perryh at pluto.rain.com]

I think I need to add a quirk entry to get umass(4) to handle my
camera, but I haven't found any coverage of this in the handbook.
Is there a "how to" somewhere (or is there something else I should
be doing)?

Upon connecting the camera, I get:

  umass0: vendor 0x0784 product 0x4300, rev 1.10/3.00, addr 2
  umass0: Get Max Lun not supported (SHORT_XFER)
  umass0: Invalid CSW: sig 0x43425355 should be 0x53425355
  umass0: Invalid CSW: sig 0x43425355 should be 0x53425355
  umass0: Invalid CSW: sig 0x43425355 should be 0x53425355
  umass0: Invalid CSW: sig 0x43425355 should be 0x53425355
  umass0: Invalid CSW: sig 0x43425355 should be 0x53425355

so I guess I need to set CAM_QUIRK_NOLUNS and something to adjust
the sig.  This is on a Dell Optiplex GX1 with 6.1, and the camera
is a Vivitar ViviCam 3825.