From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932091AbXGFSa1 (ORCPT ); Fri, 6 Jul 2007 14:30:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761351AbXGFSaU (ORCPT ); Fri, 6 Jul 2007 14:30:20 -0400 Received: from ug-out-1314.google.com ([66.249.92.174]:36594 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760891AbXGFSaS (ORCPT ); Fri, 6 Jul 2007 14:30:18 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-disposition:message-id:content-type:content-transfer-encoding; b=srQu/kNTOksVcA1+a1Ea5hJYS/S12PRoJCBiBq0PyLzeVyK06t3ccWNGcB/fERpXtFko3J0+vNaXT42butUUXsqC1r3TPiFr6Xx4IbR74DsvJQdgmJOU+8KPAXiUVVnAJHAkEL7MOGkdJJmfH0sl/2URkvMW26fhrsOhzXsl28A= From: Bartlomiej Zolnierkiewicz To: Mark Lord Subject: Re: PATA-disk named sda Date: Fri, 6 Jul 2007 20:47:10 +0200 User-Agent: KMail/1.9.6 Cc: Robert Hancock , Christoph Pleger , linux-kernel@vger.kernel.org References: <468E5420.7090605@shaw.ca> <468E82C8.7060204@rtr.ca> In-Reply-To: <468E82C8.7060204@rtr.ca> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200707062047.10265.bzolnier@gmail.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 06 July 2007, Mark Lord wrote: > Robert Hancock wrote: > >.. > > Currently the DMA, multi-sector mode, etc. are not controllable with > > hdparm with libata. libata is designed to use the fastest settings > > possible by default. In a lot of cases this messing with hdparm was only > > needed because of stupidity with the old IDE code (like DMA not being > > automatically enabled if the low-level driver was built modular). > > Actually, most of the hdparm flags were put there to help test the IDE > subsystem and to help debug the much stranger hardware it had to deal with. > > "DMA off by default" was a Linus Torvalds request, to help ensure data safety > with all of the weird and wonderful crap pre-standardization. Exactly as Mark says. I just want to add that "DMA off by default" hasn't been a case for a long time now and since 2.6.21 the config option for "DMA on by default" is also finally gone (to make a long story short: this was the best way to fix some bugs while not causing regressions, not to mention that it was defaulting to Y for years). Thanks, Bart