From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 3 Jan 2001 18:29:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 3 Jan 2001 18:28:52 -0500 Received: from deliverator.sgi.com ([204.94.214.10]:3097 "EHLO deliverator.sgi.com") by vger.kernel.org with ESMTP id ; Wed, 3 Jan 2001 18:28:41 -0500 X-Mailer: exmh version 2.1.1 10/15/1999 From: Keith Owens To: Graham Murray cc: linux-kernel@vger.kernel.org Subject: Re: 2.4.0-prelease freezes on serial event In-Reply-To: Your message of "03 Jan 2001 21:53:50 -0000." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 04 Jan 2001 10:28:35 +1100 Message-ID: <19244.978564515@kao2.melbourne.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 03 Jan 2001 21:53:50 +0000, Graham Murray wrote: >My 2.4.0-prerelease freezes solid on certain serial port events. The >ones I have seen (and are both repeatable) are when powering off the >modem and powering it on causes the system to hang solid. Also if an >incoming call is received on the telephone, the system hangs ( I >assume that this is when the modem sends 'RING' and asserts the RI >hardware signal.) Does your cpu have an APIC? SMP boxes always do, most non-mobile P6 UP systems do. If you have an APIC and assuming it is a software lockup, install the kdb patch[*]. If your box is UP, under General setup select APIC for UP then select NMI for UP. Under Kernel hacking, select kdb. You need a recent modutils, see Documentation/Changes. Ideally you should use a serial console and run a null modem to a second machine, see Documentation/serial-console.txt. Boot the kdb enhanced kernel and cat /proc/interrupts to see if NMI is non-zero. Only if NMI is non-zero, reproduce the problem. Five seconds after the lockup, the NMI watchdog should trip and drop you into kdb. The backtrace (bt) command will show where you are hung. Capture the backtrace on the second machine or hand copy the backtrace, in either case mail the backtrace to l-k. [*]ftp://oss.sgi.com/projects/kdb/download/ix86/kdb-v1.7-2.4.0-prerelease.gz - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/