From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: 2.6.32: Promise UDMA33 card refuses to work in UDMA mode Date: Mon, 04 Jan 2010 13:07:00 -0500 Message-ID: <4B422E44.1080501@garzik.org> References: <20091224181300.GA4654@flint.arm.linux.org.uk> <20091224215451.GA2476@flint.arm.linux.org.uk> <20100103002314.GA16528@flint.arm.linux.org.uk> <20100103234655.GB24920@flint.arm.linux.org.uk> <20100104103756.6cfa5b3a@lxorguk.ukuu.org.uk> <20100104133024.GA10521@flint.arm.linux.org.uk> <4B420871.2090309@garzik.org> <20100104154607.0b6e51dd@lxorguk.ukuu.org.uk> <4B421827.6050308@garzik.org> <20100104170236.5d85959f@lxorguk.ukuu.org.uk> <4B42251A.9030106@garzik.org> <20100104173835.3c5d3ea5@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-yw0-f176.google.com ([209.85.211.176]:59579 "EHLO mail-yw0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753374Ab0ADSHD (ORCPT ); Mon, 4 Jan 2010 13:07:03 -0500 Received: by ywh6 with SMTP id 6so15553123ywh.4 for ; Mon, 04 Jan 2010 10:07:01 -0800 (PST) In-Reply-To: <20100104173835.3c5d3ea5@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: linux-ide@vger.kernel.org On 01/04/2010 12:38 PM, Alan Cox wrote: >> Early SATA controllers are just PATA controllers in disguise. All SFF >> controllers want that 400ns delay. The 400ns delay should -not- be avoided. > > Its a signalling protocol requirement for PATA or a PATA controller with > a PATA/SATA bridge. What makes you think a SATA controller cares one > iota ? Because first gen SATA controllers, notably the Promise ones, were often just the same old PATA silicon logic with additional PATA<->SATA translation glue logic, rather than a pure SATA SFF implementation. >> Because several SATA controllers are SFF and use the code in question, >> the MMIO issue is relevant for the code change, even if it is irrelevant >> to drivers/ata/pata_*.c. > > and to SATA. It's simply not relevant at a protocol level to SATA which > is message passing anyway. It is not relevant to FIS-based SATA (SiI 3124, AHCI), sure. But SFF is not FIS-based SATA. Jeff