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 12:27:54 -0500 Message-ID: <4B42251A.9030106@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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gx0-f211.google.com ([209.85.217.211]:61408 "EHLO mail-gx0-f211.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753051Ab0ADR15 (ORCPT ); Mon, 4 Jan 2010 12:27:57 -0500 Received: by gxk3 with SMTP id 3so2924330gxk.1 for ; Mon, 04 Jan 2010 09:27:56 -0800 (PST) In-Reply-To: <20100104170236.5d85959f@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Russell King , linux-ide@vger.kernel.org On 01/04/2010 12:02 PM, Alan Cox wrote: >> (1b) The solution for MMIO controllers is a bit more complex: replace >> the dummy AltStatus register read with something else. > > If we had any SFF PATA controllers using MMIO. I can't find any. SATA is > different anyway. In fact we probably want to avoid such delays on a pure > SATA controller. Early SATA controllers are just PATA controllers in disguise. All SFF controllers want that 400ns delay. The 400ns delay should -not- be avoided. 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. Jeff