From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758196AbYGKMyR (ORCPT ); Fri, 11 Jul 2008 08:54:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752750AbYGKMyG (ORCPT ); Fri, 11 Jul 2008 08:54:06 -0400 Received: from bu3sch.de ([62.75.166.246]:55508 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbYGKMyF (ORCPT ); Fri, 11 Jul 2008 08:54:05 -0400 From: Michael Buesch To: David Brownell Subject: Re: [PATCH v3] Add bt8xxgpio driver Date: Fri, 11 Jul 2008 14:53:19 +0200 User-Agent: KMail/1.9.6 (enterprise 0.20070907.709405) Cc: Jiri Slaby , Andrew Morton , Stephen Rothwell , mchehab@infradead.org, linux-kernel , Marcel Holtmann References: <200807101914.10174.mb@bu3sch.de> <487651CA.6030405@gmail.com> <200807101302.12765.david-b@pacbell.net> In-Reply-To: <200807101302.12765.david-b@pacbell.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200807111453.20162.mb@bu3sch.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 10 July 2008 22:02:12 David Brownell wrote: > See Documentation/gpio.txt: > > + Note that these operations include I/O barriers on platforms > + which need to use them; drivers don't need to add them explicitly. > > That's the key thing: drivers using I/O calls should > not need to insert bus or platform specific calls to > make sure the calls take effect. Well, as I said, I am OK with an I/O-barrier, which is mmiowb(). But flushing, by reading the register back, is not acceptable for me in this case, unless someone can show me hardware that needs this. And even then I'd implement the flushing only conditionally for that hardware. -- Greetings Michael.