From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752992AbYAFFEF (ORCPT ); Sun, 6 Jan 2008 00:04:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750729AbYAFFDx (ORCPT ); Sun, 6 Jan 2008 00:03:53 -0500 Received: from [212.12.190.170] ([212.12.190.170]:45365 "EHLO raad.intranet" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750728AbYAFFDw (ORCPT ); Sun, 6 Jan 2008 00:03:52 -0500 From: Al Boldi To: Alan Cox Subject: Re: Forcing modes in libata (was: SATA buffered read VERY slow) Date: Sun, 6 Jan 2008 08:03:31 +0300 User-Agent: KMail/1.5 Cc: linux-kernel@vger.kernel.org References: <200801051641.03927.a1426z@gawab.com> <20080105163016.608b1e7f@lxorguk.ukuu.org.uk> In-Reply-To: <20080105163016.608b1e7f@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200801060803.31939.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: > Al Boldi wrote: > > What's hindering the ability to force a mode in libata, as is possible > > with the normal ide-driver? > > We want it to be correct and race free. That means we have to synchronize > all the devices on the controller, quiesce them and recompute the speeds > for each device then turn them all back on and resume command processing. > > It is quite hairy although Tejun's EH work has provided the framework for > all of this. > > For now you can boot with libata.dma=1 to select DMA on disks but not CD Great, but why isn't this in the documentation? Thanks! -- Al