From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Kernel Summit request for Discussion of future of ATA (libata) and IDE Date: Wed, 06 Aug 2008 09:44:26 +0900 Message-ID: <4898F3EA.7000507@gmail.com> References: <48976168.3020804@shaw.ca> <20080804205508.20a3f917@lxorguk.ukuu.org.uk> <48977200.3050307@shaw.ca> <20080804220619.76b94ceb@lxorguk.ukuu.org.uk> <4898EE70.1030604@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from ti-out-0910.google.com ([209.85.142.189]:50749 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753084AbYHFApE (ORCPT ); Tue, 5 Aug 2008 20:45:04 -0400 Received: by ti-out-0910.google.com with SMTP id b6so812044tic.23 for ; Tue, 05 Aug 2008 17:45:01 -0700 (PDT) In-Reply-To: <4898EE70.1030604@shaw.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Robert Hancock Cc: Alan Cox , Bartlomiej Zolnierkiewicz , James Bottomley , ksummit-2008-discuss@lists.linux-foundation.org, linux-kernel , linux-ide , Jeff Garzik Robert Hancock wrote: > Here's my first cut at it. Compile tested only. This sets most controllers > to use 32-bit PIO except for those which could potentially be on a real ISA > or other 16-bit bus. It's a bit non-obvious what to do with some of the > drivers, so input is welcome. > > This implementation doesn't check the ata_id_has_dword_io at all, since it > would only make a difference on controllers where we don't really want to > use it anyway. > > It seems like regardless of whether we do 32-bit by default or not the 32-bit > data_xfer function should be added to libata core as we have several drivers > which duplicate the same code currently.. Great, just some minor nitpicks as I don't have much idea about 16 bit ones. > +unsigned int ata_sff_data_xfer(struct ata_device *dev, unsigned char *buf, > + unsigned int buflen, int rw) > +{ > + struct ata_port *ap = dev->link->ap; > + void __iomem *data_addr = ap->ioaddr.data_addr; > + unsigned int words = buflen >> 2; dwords maybe? > + unsigned int slop = buflen & 3; > + > + /* Transfer multiple of 4 bytes */ > + if (rw == READ) > + ioread32_rep(data_addr, buf, words); > + else > + iowrite32_rep(data_addr, buf, words); > + > + /* Transfer trailing 1 byte, if any. */ 1byte? Thanks. -- tejun