Subject: Re: USB lpt and NOPRIME
To: Johnny C. Lam <>
From: Lennart Augustsson <>
List: tech-kern
Date: 02/08/2001 23:41:02
"Johnny C. Lam" wrote:

> In response to an inquiry about the USB printer code in CUPS, Michael
> Sweet, the primary author of CUPS notes:
> The FreeBSD USB printer driver resets the USB printer on open,
> unless you use the "unlptN" device.  This reset prevents some
> printers from receiving the first bytes of the print job, which
> then causes lots of spew... :(
> Is this properly a bug in the ulpt code, or a bug in the printer?  I
> notice that NetBSD doesn't have /dev/unlpt[0-9]* devices.  Should we?
> Or do we need to create some sort of quirks table for USB printers?

I'm not sure where the bug is, but the USB code mimics the lpt driver
which also resets on open (unless you use the NOPRIME bit).
And sure enough, the same problem shows up on non-USB printers.
My HP 870 doesn't print properly if I have the reset in the lpt driver.
So perhaps this is a general lpt problem.  I suspect it is really a printer bug.


        -- Lennart