From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 May 2002 10:23:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 May 2002 10:23:26 -0400 Received: from tom.hrz.tu-chemnitz.de ([134.109.132.38]:16389 "EHLO tom.hrz.tu-chemnitz.de") by vger.kernel.org with ESMTP id ; Tue, 28 May 2002 10:23:25 -0400 Date: Tue, 28 May 2002 15:54:19 +0200 From: Ingo Oeser To: David Woodhouse Cc: Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: ehci-hcd on CARDBUS hangs when stopping card service Message-ID: <20020528155419.E681@nightmaster.csn.tu-chemnitz.de> In-Reply-To: <20020523171326.GA11562@kroah.com> <3CED6E0B.8020501@pacbell.net> <28429.1022420490@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 26, 2002 at 02:41:30PM +0100, David Woodhouse wrote: > torvalds@transmeta.com said: > > Also, it's generally a good idea to "just say no" to endless loops in > > drivers. Hardware bugs _do_ happen, and it's a lot more pleasant to > > have the driver do a > > printk("Device does not respond\n"); > > than for the kernel to hang. > > Too late. On some hardware, if you try to talk to the device once it's > gone, you're already dead. Not all the world is a PeeCee. That happens even on a "PeeCee". Situation: - Normal readl() of a ioremap()ed register set of a PCI device[1]: -> machine hangs hard (no magic sysrq possible, no Ooops, no panic printed) - Several DWORD reads of the same register set succeded before and the register is wired according to the SPEC. Just to provide an argument here PS: I wish I had an PCI Analyzer available... [1] TI TMS320C6x EVM Board[2], Rev. 3 with PCI-Bridge Chip AMCC S5933[3] hanging the host side on Busmaster DMA. [2] PCI-ID: 0x104c:0x1002 [3] PCI-ID: 0x10e8:0x4750 or 0x10e8:0x807d or 0x10e8:0x809c -- Science is what we can tell a computer. Art is everything else. --- D.E.Knuth