From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] libsas, aic94xx: fix dma mapping cockups with ATA Date: Mon, 16 Jul 2007 16:19:14 -0400 Message-ID: <469BD2C2.4040002@garzik.org> References: <1184611264.3447.28.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:36087 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543AbXGPUTQ (ORCPT ); Mon, 16 Jul 2007 16:19:16 -0400 In-Reply-To: <1184611264.3447.28.camel@localhost.localdomain> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: linux-scsi James Bottomley wrote: > This one was noticed by Gilbert Wu of Adaptec: > > The libata core actually does the DMA mapping for you, so there has to > be an exception in the device drivers that *don't* do dma mapping for > ATA commands. However, since we've already done this, libsas must now > dma map any ATA commands that it wishes to issue ... and yes, this is a > horrible mess. Can you help me understand this logic? libsas must DMA map an ATA command... because libata also DMA maps an ATA command? That does not make sense to me. Jeff