From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raphael Assenat Date: Mon, 10 Apr 2006 01:10:11 +0000 Subject: Re: Parallel port problems on Sun Ultra10 Message-Id: <20060410011011.GA22569@aramis.lan.raphnet.net> List-Id: References: <1144596830.4439295e52873@imp1-g19.free.fr> In-Reply-To: <1144596830.4439295e52873@imp1-g19.free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On Sun, Apr 09, 2006 at 05:33:50PM +0200, Christophe Jacquet wrote: > When I type " echo 'Hello world' >/dev/lp0 ", I get the message: > > lp0: ECP mode > > The string gets printed on the printer. > > Then, Linux crashes. I get no more messages. The Bash prompt never comes back. I > can interact with OBP by hitting "Stop-A", and reboot the machine. Hi, this reminds me of a problem I had a few week ago while playing with an homebuild parallel port project. The machine would lock totally, but as soon as I disconnected the circuit from the port the machine would unlock. Maybe you could try disconnecting the printer and see what happens? Here are more details about the problem I observed: When the parallel port interrupt is enabled, the machine hangs as long as the ACK pin is held low. I observed that the parport interrupt count in /proc/interrupt were higher after each hang. It looks to me like the parport interrupt is level triggered instead of edge triggered. I wanted try on x86 hardware to see if the problem also happens before posting, but I decided to post anyway when I saw this message. I observed this on a 2.6.16-rc6-git-something. Regards, Raphael Assenat