From owner-freebsd-current Tue May 9 06:19:15 1995 Return-Path: current-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id GAA13820 for current-outgoing; Tue, 9 May 1995 06:19:15 -0700 Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.34]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id GAA13813 for ; Tue, 9 May 1995 06:19:05 -0700 Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.9/8.6.9) id XAA08055 for current@freebsd.org; Tue, 9 May 1995 23:15:11 +1000 Date: Tue, 9 May 1995 23:15:11 +1000 From: Bruce Evans Message-Id: <199505091315.XAA08055@godzilla.zeta.org.au> To: current@FreeBSD.org Subject: misadventures with parallel port tcp/ip Sender: current-owner@FreeBSD.org Precedence: bulk I tried the parallel port tcp/ip interface and found the following problems: 1) The BIOS probe fails if lp0 is up at the other end. I have two printer ports and lpt0 configured with `port?' so this caused lp0 to take turns working on the port that was not connected at boot time. 2) The system paniced with a null pointer trap in ifa_ifwithaddr() when I tried the following misconfiguration: ifconfig lp0 inet a0 b0 # a0 and b0 are in /etc/hosts route add b0 a0 # back to front route change a0 A NULL gateway was passed from route_output(). 3) Too much is done at a high ipl. I tried replacing the splhigh()s by splimp()s and everything continued to work even with 39000 interrupts/sec in the background (16000 from pcaudio, 2 * 11500 from 16450's). Ping latency increased from 2ms to 9-20ms with all these interrupts on a 486DX/33. 4) net_imask isn't initialized right in isa.c unless SLIP or PPP is configured. It needs to contain the lpt bit or perhaps all of tty_imask if lpt and INET are configured, at least while lp0 is up. This is approximately always. Bruce