From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: sata_sil and byte-aligned mmio Date: Mon, 16 Oct 2006 12:19:01 +0900 Message-ID: <4532FA25.4080002@gmail.com> References: <452D69E6.9050606@mvista.com> <4532F9B7.1070901@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0102.google.com ([64.233.162.197]:43360 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1751400AbWJPDTJ (ORCPT ); Sun, 15 Oct 2006 23:19:09 -0400 Received: by nz-out-0102.google.com with SMTP id z3so461678nzf for ; Sun, 15 Oct 2006 20:19:08 -0700 (PDT) In-Reply-To: <4532F9B7.1070901@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org Cc: jeff@garzik.org, linux-ide@vger.kernel.org Tejun Heo wrote: > Hello, Kevin. > > Kevin Hilman wrote: >> Tejun, >> >> A while back you provided a patch for sata_sil to use PCI IO space since >> so that it can work on hardware that doesn't support byte-aligned MMIO. >> >> I'd like to see a fix for this pushed upstream, but IIRC, Jeff Garzik >> prefers that the driver be fixed up to use 32-bit aligned MMIO instead >> of making the driver use IO space. >> >> If you can point me in the right direction, as to where the >> byte-alignement assumtions are, I can fix up the driver and test it on >> my hardware. > > Byte-aligned IO accesses are in the default ATA operations - > ata_tf_load/read, ata_check_status, ata_exec_command, > ata_std_dev_select, all the bmdma ops, etc... Basically, traditional > ATA interface is designed to use byte-aligned registers to operate. > > sil3112 family of controllers allow all those ops implemented using > 32bit ops, so you need to implement sata_sil's own methods to replace > those standard byte-aligned ops. I don't think it's gonna be too > difficult. Oh, and just in case you don't have them already, the specs are available at the following URL. http://gkernel.sourceforge.net/specs/sii/ -- tejun