Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753486AbaJVRT7 (ORCPT ); Wed, 22 Oct 2014 13:19:59 -0400 Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:41082 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751899AbaJVRT5 (ORCPT ); Wed, 22 Oct 2014 13:19:57 -0400 Date: Wed, 22 Oct 2014 18:19:42 +0100 From: Russell King - ARM Linux To: Mathieu Poirier Cc: Catalin Marinas , stefano.stabellini@eu.citrix.com, ezequiel.garcia@free-electrons.com, Liviu Dudau , Thomas Petazzoni , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ARM: supplementing IO accessors with 64 bit capability Message-ID: <20141022171942.GC27405@n2100.arm.linux.org.uk> References: <1413993983-17310-1-git-send-email-mathieu.poirier@linaro.org> <20141022161155.GB27405@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 22, 2014 at 06:22:09PM +0200, Mathieu Poirier wrote: > I had this conversation with a colleague who reviewed the work. If > the architecture is < 5 the __raw_ versions aren't included and the > compiler won't complain until someone tries to use the macros. We > achieve the same result - the macros aren't accessible when the > architecture doesn't support it - while saving an #if condition in the > file. > > I'm not strongly opinionated on this - I can enclose the macros in an > #if statement. What you're missing is that some driver may test for their presence by doing: #ifndef readq_relaxed ... do something else which would now break as a detection method, as the macro is always defined no matter whether it's present or not. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/