From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH] aic7xxx driver. Restrict DMA to 32bit for 29320LPE Adaptec SCSI controller Date: Thu, 20 Sep 2007 19:41:47 -0500 Message-ID: <1190335307.3360.66.camel@localhost.localdomain> References: <1183207551.14436.15.camel@linux.site> <1190300889.31372.4.camel@linux.site> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from hancock.steeleye.com ([71.30.118.248]:38488 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752272AbXIUAlv (ORCPT ); Thu, 20 Sep 2007 20:41:51 -0400 In-Reply-To: <1190300889.31372.4.camel@linux.site> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Anil K. Ravindranath" Cc: Linux-scsi@vger.kernel.org On Thu, 2007-09-20 at 08:08 -0700, Anil K. Ravindranath wrote: > Hi, > > We have not heard any comments or inputs on this patch. > > With regards, > Anil > > On Sat, 2007-06-30 at 05:45 -0700, Anil K. Ravindranath wrote: > > Subject: [PATCH] aic7xxx driver. Restrict DMA to 32bit for 29320LPE > > Adaptec SCSI controller > > > > Contribution: > > > > Anil Ravindranath > > > > Issue: > > > > Data Bursts that cross from 32- to 64-Bit address space have incorrect > > address for 29320LPE. This leads to potential data corruption. Where do you think you see this happening? The block layer has a dma_boundary parameter (basically a mask which it refuses to allow dma to cross). By default this is set to 4GB (because a lot of PCI cards have difficulty going from non-DAC to DAC). The aic79xx driver does nothing to alter this, so you shouldn't be seeing any DMA segments crossing the 4GB boundary. James