From owner-freebsd-hackers@FreeBSD.ORG Fri Aug 3 17:54:53 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 650F8106566C for ; Fri, 3 Aug 2012 17:54:53 +0000 (UTC) (envelope-from dieterbsd@engineer.com) Received: from mailout-us.gmx.com (mailout-us.gmx.com [74.208.5.67]) by mx1.freebsd.org (Postfix) with SMTP id 091CD8FC08 for ; Fri, 3 Aug 2012 17:54:52 +0000 (UTC) Received: (qmail 17820 invoked by uid 0); 3 Aug 2012 17:13:22 -0000 Received: from 67.206.185.79 by rms-us011.v300.gmx.net with HTTP Content-Type: text/plain; charset="utf-8" Date: Fri, 03 Aug 2012 13:13:21 -0400 From: "Dieter BSD" Message-ID: <20120803171322.298400@gmx.com> MIME-Version: 1.0 To: freebsd-hackers@freebsd.org X-Authenticated: #74169980 X-Flags: 0001 X-Mailer: GMX.com Web Mailer x-registered: 0 Content-Transfer-Encoding: 8bit X-GMX-UID: 5WNucPQV3zOlNR3dAHAhwTF+IGRvb4Aj Subject: Re: How to diagnose system freezes? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Aug 2012 17:54:53 -0000 Adrian writes: > the "cycle over a short period" may not be the driver writing the same > crap to the card. I've seen similar failure modes in windows where > during playback, if the system hangs for whatever reason, the card > plays the last sample over and over in a loop. Ok, that makes sense.  So it could be any device driver. Seems like diagnosing a device driver that is stuck in an infinite loop (or equivalent) with all interrupts shut off would be rather difficult.