Usb printers take the same port deterministically?

[Scott Gasch]

Hi,

I have two usb printers on my freebsd machine and I'm using cups.  One of
the things I've done is publish a raw (no driver) printer for each of them
and use that to share them with other machines in the house that have
drivers.

My problem is that every once in a while, when I boot up, the order of the
printers on the usb ports seems to change.  For example, right now I've got:

Jun  4 11:24:34 foo kernel: ulpt0: <Brother HL-2140 series, class 0/0, rev
2.00/1.00, addr 2> on uhub1
Jun  4 11:24:34 foo kernel: ulpt0: using bi-directional mode
Jun  4 11:28:13 foo kernel: ulpt1: <EPSON USB2.0 Printer (Hi-speed), class
0/0, rev 2.00/1.00, addr 2> on uhub7


But when I lost power the other night the machine came up with them reversed
-- the brother on ulpt1 and the epson on ulpt0.

As far as I can tell, cups printers.conf ties to a particular port.  So, you
can probably see where this is going... when they bind in the wrong order
and someone prints I get a ton of crap printed out and waste a ton of paper.
 How can I make it so that a particular printer binds to a particular usb
port deterministically?

Thx,
Scott