From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761253Ab0J0N1p (ORCPT ); Wed, 27 Oct 2010 09:27:45 -0400 Received: from gate.crashing.org ([63.228.1.57]:57478 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756640Ab0J0N1m (ORCPT ); Wed, 27 Oct 2010 09:27:42 -0400 Subject: Re: Pegasos OHCI bug (was Re: PROBLEM: memory corrupting bug, bisected to 6dda9d55) From: Benjamin Herrenschmidt To: pacman@kosh.dhis.org Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, matt@genesi-usa.com In-Reply-To: <20101027085738.1837.qmail@kosh.dhis.org> References: <20101027085738.1837.qmail@kosh.dhis.org> Content-Type: text/plain; charset="UTF-8" Date: Thu, 28 Oct 2010 00:27:24 +1100 Message-ID: <1288186044.2236.25.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Since then, the silence has been deafening. > > My assumption now is that this is not ever getting fixed. I'm certainly not > able to fix it. I'm not a even kernel programmer! I got far enough to > diagnose the cause just with the "add more printk's and boot it again" > technique. Hundreds of reboots trying to figure it out. I was a conscientious > bug-reporter, I thought. I'm happy to help you fix it but I'm travelling at the moment and won't have much time for a couple of weeks. Cheers, Ben. > I could pull the PCI card and be done with it. I never used those USB ports > anyway. But after all the suffering I went through to find this bug... the > crashing e2fsck's and consequent filesystem corruption... I hate the idea of > surrendering to it. There are possibly other affected users who I'd be > abandoning to suffer similarly in the future. > > For the last week I've studied OpenFirmware as hard as I can. I read the spec > cover to cover. And the USB annex, and the PCI annex. But I'm still lost in > all the different address formats. > > I took my best guess on how to handle this problem, and ran with it, ending > up with a 97-line Forth script, and that was just to get a virtual address, > not to actually do anything with it, and it used a hardcoded device path. But > it didn't work, all I got was an "invalid pointer" error. I made another > guess at something that wasn't documented anywhere (the fact that this stuff > is insufficiently documented is the one thing I can state with complete > confidence!) and out came a successful translation to a virtual address: 0. > > If I'm the only one fighting this bug, the bug wins. >