ulpt hangs on offline status

[Sandy Rutherford]

I have an Entrega USB->Centronics adapter attached to an HP Laserjet
III.  When the printer (printer name is lp) runs out of paper, I get
the usual 

   "waiting for lp to become ready (offline?)" 

message from lpq.  However, when I refill the printer and bring it
back online, ultp, seems not to notice.  It stays stuck in this state.
With a direct parallel connection, the status is updated and the
printer queue starts moving again.

I have found that the only way to get ultp to update the status is to
disconnect and reconnect the USB cable, forcing a detach/attach
event.

This is with FreeBSD 4.10 / i386.

1. Has anybody else seen this behaviour?

2. Is it a driver bug or a problem with the Entrega adapter?  The
   specs of my adapter and USB controller are below.

3. Does anybody know of a patch to ultp.c to fix this problem?

4. Any ideas for a (software) workaround, such as a way to force a soft
   detach/attach? 

[root at szamoca:14] usbdevs -v -d
Controller /dev/usb0:
addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), Intel(0x0000), rev 1.00
  uhub0
 port 1 powered
 port 2 addr 2: full speed, power 98 mA, config 1, Centronics connector(0x0006), Entrega(0x1645), rev 1.00
   ulpt0

I am willing to muck around with the driver to try to fix this myself,
but it would be useful to know if anybody else has seen or worked on
this problem.

Thanks,
Sandy