From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757789Ab0JSVEA (ORCPT ); Tue, 19 Oct 2010 17:04:00 -0400 Received: from gate.crashing.org ([63.228.1.57]:34395 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754012Ab0JSVD7 (ORCPT ); Tue, 19 Oct 2010 17:03:59 -0400 Subject: Re: PROBLEM: memory corrupting bug, bisected to 6dda9d55 From: Benjamin Herrenschmidt To: Segher Boessenkool Cc: pacman@kosh.dhis.org, Mel Gorman , linux-mm@kvack.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <56111.84.105.60.153.1287521237.squirrel@gate.crashing.org> References: <20101019181021.22456.qmail@kosh.dhis.org> <56111.84.105.60.153.1287521237.squirrel@gate.crashing.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 20 Oct 2010 08:02:48 +1100 Message-ID: <1287522168.2198.5.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 On Tue, 2010-10-19 at 22:47 +0200, Segher Boessenkool wrote: > > It looks like it is the frame counter in an USB OHCI HCCA. > 16-bit, 1kHz update, offset x'80 in a page. > > So either the kernel forgot to call quiesce on it, or the firmware > doesn't implement that, or the firmware messed up some other way. I vote for the FW being on crack. Wouldn't be the first time with Pegasos. It's an OHCI or an UHCI in there ? Can you try in prom_init.c changing the prom_close_stdin() function to also close "stdout" ? if (prom_getprop(_prom->chosen, "stdin", &val, sizeof(val)) > 0) call_prom("close", 1, 0, val); + if (prom_getprop(_prom->chosen, "stdout", &val, sizeof(val)) > 0) + call_prom("close", 1, 0, val); See if that makes a difference ? Last option would be to manually turn the thing off with MMIO in yet-another pegasos workaround in prom_init.c. Cheers, Ben.