RELENG7 using lpt causes panic

[Adrian Wontroba]

On Tue, Jan 08, 2008 at 01:52:40PM +0700, Eugene Grosbein wrote:
> On Tue, Jan 08, 2008 at 03:08:57AM +0000, Adrian Wontroba wrote:
> 
> > I've recently switched some of my home systems to RELENG7.
> > 
> > All seemed fairly well until I tried printing a CUPS test page on my
> > backup and print server to an elderly Laserjet IIIp, where I seem to
> > have a reproducible panic. It has happened twice.  This is painful, as
> > I have a big home fileystem (striped over two mirrors over most of two
> > 500 GB disks). The gmirror syncronisation and background fsck leave the
> > system close to unusable for hours while they fight over the disks.
> > 
> > I was somewhat startled that something so basic as printing causes a
> > panic. There have been no hardware changes since I last printed under
> > RELENG6, but I don't print often, so hardware decay is a possibility.
> > 
> > Is this a known problem? If not, I'll take the time to try various tests
> > (with /home unmounted) and raise a PR.
> 
> There is a PR about this problem with workaround:
> http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/117973
> 
> Eugene Grosbein

My thanks to Eugene for the pointer to a known workaround
(switching the printer driver to extended mode before printing with
'/usr/sbin/lptcontrol -e -d /dev/lpt0.ctl') and to John for explaining
the underlying issue and intentions for fixing it.

-- 
Adrian Wontroba
Heisenberg may have done it.