From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753351Ab2DMOSj (ORCPT ); Fri, 13 Apr 2012 10:18:39 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:55907 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631Ab2DMOSh (ORCPT ); Fri, 13 Apr 2012 10:18:37 -0400 Message-ID: <4F8835B8.2060400@garzik.org> Date: Fri, 13 Apr 2012 10:18:32 -0400 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120316 Thunderbird/11.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: [RFC] enable FUA support in libata References: <20120413081104.GA4953@gmail.com> In-Reply-To: <20120413081104.GA4953@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/13/2012 04:11 AM, Zheng Liu wrote: > Hi Jeff and list, > > Recently I met a problem about FUA support of SATA disk. In my machine, > it has a SATA disk that supports FUA feature. But after system starts > up, it displays that the disk cannot support FUA from dmesg. > > I notice this commit (c3c013a2). It disables FUA support in all of SATA > disk. But the commit log is too simple to know why we should disable > FUA support in libata. Could you please explain it? Thank you. FUA support in the block layer wanted speed and guarantees that early FUA drives were simply not providing.