From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: 2.6.24-rc & SB600 AHCI no go on >=4GB of RAM Date: Wed, 14 Nov 2007 13:17:35 +0100 Message-ID: <200711141317.35746.ak@suse.de> References: <198606.73895.qm@web52608.mail.re2.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from cantor.suse.de ([195.135.220.2]:33614 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751611AbXKNMVb (ORCPT ); Wed, 14 Nov 2007 07:21:31 -0500 In-Reply-To: <198606.73895.qm@web52608.mail.re2.yahoo.com> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Srihari Vijayaraghavan Cc: Ingo Molnar , Thomas Gleixner , Tejun Heo , linux-ide@vger.kernel.org On Wednesday 14 November 2007 12:55, Srihari Vijayaraghavan wrote: > [Sorry to reply to my own email thread] > > Srihari Vijayaraghavan wrote: > ... > > > No problems. Here's the log of unworking kernel with IOMMU turned on. > > Basically it goes on reseting the SATA ports throwing many errors (none > > are present in 2.6.23 or on 2.6.24-rc with mem=3500M) for many minutes at > > which point I do a power reset :-(. > > > > Also the log of the working kernel with IOMMU but with mem=3500M is also > > attached for the record. It's basically the same above kernel just with > > the added parameter. > > Gentlemen, > > This changeset has introduced a regression in 2.6.24-rc, such that my > machine boots no more: Hmm, you got an AHCI controller that does not do 64bit DMA masks? Or do you have CONFIG_IOMMU_DEBUG enabled? Anyways, not being able to deal with merged SG lists must be some driver or hardware bug. I would stick some printks into gart_map_sg() and try to find out where the failing DMA is initiatiated and then split it into multiple IO submissions at the caller level. -Andi