From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752891Ab1HDJo3 (ORCPT ); Thu, 4 Aug 2011 05:44:29 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:48509 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751675Ab1HDJoY (ORCPT ); Thu, 4 Aug 2011 05:44:24 -0400 Date: Thu, 4 Aug 2011 11:44:19 +0200 From: Tejun Heo To: Brian Norris Cc: linux-ide@vger.kernel.org, Valdis.Kletnieks@vt.edu, "Rafael J. Wysocki" , Jeff Garzik , Michael Leun , linux-kernel@vger.kernel.org, Jian Peng , Kevin Cernekee Subject: Re: ahci_start_engine compliance with AHCI spec Message-ID: <20110804094419.GA2731@htj.dyndns.org> References: <20110713131407.GN2872@htj.dyndns.org> <20110721084917.GE3455@htj.dyndns.org> <20110722090317.GH2622@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Aug 02, 2011 at 05:06:13PM -0700, Brian Norris wrote: > Can DRQ be set from 0->1 without a software-initiated action? I didn't > think it was directly tied to PHY events, and so we can fairly well > predict that it will remain 0. Sure it can. It's updated by Register D2H FISes sent by the device. It can change after a PHY event; otherwise, I don't think it would get set during init without any command in flight, right? > Yes, I believe the hardware designers know how buggy this is...but > it's still worth some effort to fix the software as well as possible > for current hardware behavior. Yeap, sure, let's get it working for majority of cases. I just wanted to point out that the hardware eventually needs to be fixed. Thanks. -- tejun