From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 05/14] libata: make ->data_xfer return the number of consumed bytes Date: Thu, 29 Nov 2007 14:36:30 -0500 Message-ID: <474F14BE.2050502@garzik.org> References: <1196346817387-git-send-email-htejun@gmail.com> <11963468181417-git-send-email-htejun@gmail.com> <20071129155546.694c6c45@the-village.bc.nu> <474EE394.6020604@gmail.com> <20071129174259.6a1edc88@the-village.bc.nu> <474EFE58.701@gmail.com> <20071129182409.2fcd66d6@the-village.bc.nu> 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]:60129 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751007AbXK2Tgf (ORCPT ); Thu, 29 Nov 2007 14:36:35 -0500 In-Reply-To: <20071129182409.2fcd66d6@the-village.bc.nu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Tejun Heo , linux-ide@vger.kernel.org, liml@rtr.ca, albertl@mail.com, jens.axboe@oracle.com Alan Cox wrote: >> DMA alignment is host restriction so I think it belongs to ata_host if >> we ever need it. Do you know of any controller which require such >> thing? No need to add complexity when it's not necessary. > > If we ever get the blasted inic162x working then that appears to have > some alignment limits. At least the docs say the DMA buffers must be quad > word aligned and sized (although it doesn't describe what occurs if the > total length of xfer disagrees with the buffers) Most DMA has alignment limits, for the front not the back of the buffer. Jeff