Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932783AbXASAwz (ORCPT ); Thu, 18 Jan 2007 19:52:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932801AbXASAwz (ORCPT ); Thu, 18 Jan 2007 19:52:55 -0500 Received: from mail.gmx.net ([213.165.64.20]:36507 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S932783AbXASAwy (ORCPT ); Thu, 18 Jan 2007 19:52:54 -0500 X-Authenticated: #5039886 Date: Fri, 19 Jan 2007 01:52:51 +0100 From: =?iso-8859-1?Q?Bj=F6rn?= Steinbrink To: Robert Hancock Cc: linux-kernel@vger.kernel.org, Larry Walton , jeff@garzik.org, htejun@gmail.com, jens.axboe@oracle.com Subject: Re: SATA exceptions with 2.6.20-rc5 Message-ID: <20070119005251.GA32669@atjola.homenet> Mail-Followup-To: =?iso-8859-1?Q?Bj=F6rn?= Steinbrink , Robert Hancock , linux-kernel@vger.kernel.org, Larry Walton , jeff@garzik.org, htejun@gmail.com, jens.axboe@oracle.com References: <45B00C4E.4040803@shaw.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <45B00C4E.4040803@shaw.ca> User-Agent: Mutt/1.5.13 (2006-08-11) X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1777 Lines: 38 On 2007.01.18 18:09:50 -0600, Robert Hancock wrote: > I heard from Larry Walton who was apparently seeing this problem as > well. He tried my recent "sata_nv: cleanup ADMA error handling v2" patch > and originally thought it fixed the problem, but it turned out to only > make it happen less often. > > I wouldn't expect that patch to have an effect on this problem. If it > seems to reduce the frequency that would tend to be further evidence of > some kind of timing-related issue where the code change just happens > to make a difference. > > I'll see if I can come up with a debug patch for people having this > problem to try, which prints out when a flush command is issued and what > interrupts happen when a flush is pending. > > There is one important difference between ADMA and non-ADMA mode for > non-DMA commands like flushes, which didn't come to mind before: ADMA > mode uses MMIO registers on the controller whereas non-ADMA mode uses > legacy IO registers. Posted write flushing is a concern with MMIO > registers but not with PIO, the libata core is supposed to handle this > but maybe it doesn't in some case(s). In fact, just looking at > libata-sff.c there's this comment on the ata_exec_command_mmio function: > > * FIXME: missing write posting for 400nS delay enforcement > > That seems a bit suspicious.. That would imply that disabling adma via a module parameter should make the issue go away, right? I'll try to have a test run with adma disabled over night then. Thanks, Bj?rn - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/