From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: About forcing 32bit DMA patch for AMD690G(SB600) Date: Fri, 25 Jan 2008 09:21:55 +0900 Message-ID: <47992BA3.3070104@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from rv-out-0910.google.com ([209.85.198.188]:6002 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751498AbYAYAWC (ORCPT ); Thu, 24 Jan 2008 19:22:02 -0500 Received: by rv-out-0910.google.com with SMTP id k20so456653rvb.1 for ; Thu, 24 Jan 2008 16:22:01 -0800 (PST) In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Shane Huang Cc: sriharivijayaraghavan@yahoo.com.au, linux-ide@vger.kernel.org Hello, Shane. Sorry about the delay. Got caught up in other stuff. Shane Huang wrote: > Quoting Tejun: >> Uh-oh, wait a bit. Nope. Until we figure out what the something >> else > is >> and positively verify 64bit DMA works fine, the quirk stays in. > > Our HW engineer has confirmed that our SB600 SATA controller indeed > has some MSI issue, and we do not have any workaround. > > The workaround "quirk_msi_intx_disable_bug" to SB700 SATA controller > can NOT work to SB600 SATA controller in my debug, while disablement > to RS690 MSI in kernel source can fix it. Hmmm... Okay. Is the SB600 SATA controller culprit or the north bridge - RS690? If the former is the case, proper way to work around it is to add AHCI_HFLAG_NO_MSI for SB600 AHCI. > As to the SB600 64 bit DMA capacity, do you have any methods to do > further verification? I do NOT find any problem in my debug after I > disabled RS690 MSI in kernel 2.6.24-rc7. The problem is that we didn't actually prove anything. In the tests you've done, pci=nomsi didn't fix the problem but disable_all_msi quirk did. pci=nomsi and disable_all_msi quirk are identical. Also, Srihari's problem was not reproduced, so currently we can't say much from the test results. Srihari, do you still have the system around? Thanks. -- tejun