From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: sata_svw data corruption, strange problems Date: Mon, 23 Jun 2008 17:22:36 +0900 Message-ID: <485F5D4C.90609@kernel.org> References: <20080617093602.GA28140@elf.ucw.cz> <485EF061.3010601@kernel.org> <20080623082055.GB1850@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:54408 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753282AbYFWIXs (ORCPT ); Mon, 23 Jun 2008 04:23:48 -0400 In-Reply-To: <20080623082055.GB1850@elf.ucw.cz> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Pavel Machek Cc: kernel list , benh@kernel.crashing.org, jgarzik@pobox.com, IDE/ATA development list , Trivial patch monkey Pavel Machek wrote: > Hi! > >>> I see strange problems on machine with sata_svw. The machine seems to >>> corrupt data every few days (ext3 error, dir index corrupted), and has >>> some other very strange problems (keyboard misbehaves, pulling out >>> SATA disk cures it, see >>> https://bugzilla.novell.com/show_bug.cgi?id=400772 ). >>> >>> Then I got to the comment >>> >>> writeb(dmactl | ATA_DMA_START, mmio + ATA_DMA_CMD); >>> /* There is a race condition in certain SATA controllers >>> that can be seen when the r/w command is given to the controller >>> before the host DMA is started. On a Read command, the controller > ... >>> ...and that would certainly explain what we are seeing. Are >>> serverworks controllers broken by design? >> The comment looks like a warning to me as the DMA engine is started >> before the command is issued to the drive as explained in the next >> comment. > > Ok, what about this? > > --- > > Clarify data corruption comment. > > Signed-off-by: Pavel Machek Acked-by: Tejun Heo -- tejun