From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH 0/2] libata: implement 32-bit transfers for PIO mode Date: Sun, 17 Feb 2008 22:31:34 +0000 Message-ID: <20080217223134.1c61809b@core> References: <20080217211810.GA15001@1wt.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:49769 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753972AbYBQWkC (ORCPT ); Sun, 17 Feb 2008 17:40:02 -0500 In-Reply-To: <20080217211810.GA15001@1wt.eu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Willy Tarreau Cc: jeff@garzik.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org > Thus, I have implemented the 32-bit mode to bring the performance back > to the level of the old IDE driver. I jumped from 1.5 MB/s to 2.5 MB/s, > which is an important difference at this level of performance, especially > when large files are read. The 32-bit mode is enabled using the ioctl > which is already implemented but only accepts a null value. Excellent, that has been on my TODO list for some time and I'd only gotten as far as putting into the ISA/VLB drivers rather than generally testing. I'm not however sure this should be a DFLAG but should be an alernative ata_data_xfer method - I say that because VLB needs to wrap it and some controllers have quirky rules for 32bit xfers. (Also some small number of pre ATA disks can't handle the different timing cycles from a 32bit ISA I/O being redirected their way). Alan