kern/46225: printing to /dev/lpt0 hangs in lptwrite(), probably lptwrite2

[Petar Bogdanovic <petar%smokva.net@localhost>]

>Number:         46225
>Category:       kern
>Synopsis:       printing to /dev/lpt0 hangs in lptwrite(), probably lptwrite2
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 19 03:45:00 +0000 2012
>Originator:     Petar Bogdanovic
>Release:        NetBSD 6.0_BETA (16.03.2012)
>Organization:
>Environment:
        amd64
>Description:
        Since upgrading from 5.99.54 to 6.0_BETA, my parallel printer
        stopped working.  A process writing to /dev/lpt0 (cups or cat)
        ends up waiting forever in lptwrite(), probably lptwrite2.

        $ ident /netbsd-5.99.54 | grep lpt
             $NetBSD: lpt.c,v 1.78 2009/11/25 14:28:50 rmind Exp $
             $NetBSD: lpt_isa.c,v 1.68 2009/11/23 02:13:47 rmind Exp $
             $NetBSD: lpt_puc.c,v 1.14 2008/03/07 17:15:52 cube Exp $
             $NetBSD: ulpt.c,v 1.86 2011/03/29 07:48:13 mbalmer Exp $

        $ ident /netbsd-6.0_BETA | grep lpt
             $NetBSD: lpt.c,v 1.78 2009/11/25 14:28:50 rmind Exp $
             $NetBSD: lpt_isa.c,v 1.68 2009/11/23 02:13:47 rmind Exp $
             $NetBSD: lpt_puc.c,v 1.14 2008/03/07 17:15:52 cube Exp $
             $NetBSD: ulpt.c,v 1.88 2011/12/23 00:51:47 jakllsch Exp $

>How-To-Repeat:
        Write to /dev/lpt0 while running 6.0_BETA.
>Fix:
        none