Subject: kern/7101: lpt(4) driver "no prime" issues
To: None <gnats-bugs@gnats.netbsd.org>
From: Brett Slager <bds@snarf.thnet.com>
List: netbsd-bugs
Date: 03/07/1999 18:05:03
>Number: 7101
>Category: kern
>Synopsis: lpt(4) driver "no prime" issues
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: kern-bug-people (Kernel Bug People)
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sun Mar 7 15:20:00 1999
>Last-Modified:
>Originator: Brett Slager
>Organization:
>Release: NetBSD-current and other releases
>Environment:
System: NetBSD snarf.thnet.com 1.3G NetBSD 1.3G (SNARF) #0: Sun Aug 30 16:42:17 EST 1998 bds@snarf.thnet.com:/home/tortise/netbsd/src/sys/arch/i386/compile/SNARF i386
>Description:
Richard Rauch's <rauch@eecs.ukans.edu> recent mail to netbsd-users
reminded me of this problem... this pr is so no one forgets.
Attempts to send a job to a parallel printer while another job is
printing out of the printer's buffer can initialize the printer and
ruin both print jobs. There are probably printers out there
unaffected by this but every printer I've used would do this.
>How-To-Repeat:
Try to set up a printer and find that multiple jobs step on each
other. Get angry. Read driver source and the workaround is revealed.
>Fix:
man 4 lpt mentions minor bit 64 as disabling init on the port,
perhaps this should be made the default device behavior
(principle of least suprise) or possibly only the first open
on a printer device should signal an INIT.
At the very least this whole affair should be documented and
MAKEDEV should make "no prime" device nodes too.
>Audit-Trail:
>Unformatted: