Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751833AbaGTJvz (ORCPT ); Sun, 20 Jul 2014 05:51:55 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:49697 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751523AbaGTJvw (ORCPT ); Sun, 20 Jul 2014 05:51:52 -0400 Message-ID: <53CB9134.7080705@gmail.com> Date: Sun, 20 Jul 2014 17:51:48 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Richard Weinberger CC: Lennox Wu , Arnd Bergmann , Lars-Peter Clausen , Guenter Roeck , Greg Kroah-Hartman , Dmitry Torokhov , linux-iio@vger.kernel.org, Benjamin Herrenschmidt , Tom Gundersen , Thierry Reding , Marek Vasut , Liqin Chen , msalter@redhat.com, linux-pwm@vger.kernel.org, devel@driverdev.osuosl.org, linux-watchdog@vger.kernel.org, linux-input@vger.kernel.org, "linux-kernel@vger.kernel.org" , knaack.h@gmx.de, Martin Schwidefsky , Mischa.Jonker@synopsys.com, jic23@kernel.org, Geert Uytterhoeven , cmetcalf@tilera.com, Martin Schwidefsky , heiko.carstens@de.ibm.com Subject: Re: [PATCH] drivers: Let several drivers depends on HAS_IOMEM for 'devm_ioremap_resource' References: <201407130545.23004.marex@denx.de> <6823014.2plXDE9VA9@wuerfel> <53C7A819.40403@metafoo.de> <6485666.LVFO2YCEQx@wuerfel> <53C8114D.30601@nod.at> <53C86C10.2000608@gmail.com> <53C8CE59.3060103@nod.at> <53C8FA78.1020501@gmail.com> <53C8FC1E.9090003@nod.at> <53C9612E.3040001@gmail.com> <53CB801D.1030603@gmail.com> <53CB8FBF.2070206@nod.at> In-Reply-To: <53CB8FBF.2070206@nod.at> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/20/2014 05:45 PM, Richard Weinberger wrote: > > > Am 20.07.2014 10:38, schrieb Chen Gang: >> On 07/19/2014 02:02 AM, Chen Gang wrote: >>>> 2014-07-18 18:51 GMT+08:00 Richard Weinberger : >>>>> Am 18.07.2014 12:44, schrieb Chen Gang: >>>>>> On 07/18/2014 03:35 PM, Richard Weinberger wrote: >>>>>>> Am 18.07.2014 02:36, schrieb Chen Gang: >>>>>>>> >>>>>>>> On 07/18/2014 02:09 AM, Richard Weinberger wrote: >>>>>>>>> Am 17.07.2014 12:48, schrieb Arnd Bergmann: >>>>>>>>>> AFAICT, NO_IOMEM only has a real purpose on UML these days. Could we take >>>>>>>>>> a shortcut here and make COMPILE_TEST depend on !UML? Getting random stuff >>>>>>>>>> to build on UML seems pointless to me and we special-case it in a number of >>>>>>>>>> places already. >>>>>>>>> >>>>>>>>> If UML is the only arch without io memory the dependency on !UML seems >>>>>>>>> reasonable to me. :-) >>>>>>>>> >>>>>>>> >>>>>>>> For me, if only uml left, I suggest to implement dummy functions within >>>>>>>> uml instead of let CONFIG_UML appear in generic include directory. And >>>>>>>> then remove all HAS_IOMEM and NO_IOMEM from kernel. >>>>>>> >>>>>>> Erm, this is something completely different. >>>>>>> I thought we're focusing on COMPILE_TEST? >>>>>>> >>>>>> >>>>>> COMPILE_TEST is none-architecture specific, but UML is. So in generic >>>>>> include folder, if we're focusing on choosing whether COMPILE_TEST or >>>>>> UML, for me, I will choose COMPILE_TEST. >>>>>> >>>>>> If we're not only focusing on COMPILE_TEST, for me, if something only >>>>>> depend on one architecture, I'd like to put them under "arch/*/" folder. >>>>>> >>>>>> Especially, after that, we can remove all HAS_IOMEM and NO_IOMEM, nobody >>>>>> has to think of them again. :-) >>>>> >>>>> And then we end up with a solution that on UML a lot of completely useless >>>>> drivers are build which fail in various interesting manners because you'll >>>>> add stubs for all kinds of io memory related functions to arch/um/? >>>>> We had this kind of discussion already. You'll need more than ioremap... >>>>> >>>>> I like Arnd's idea *much* more to make COMPILE_TEST depend on !UML. >>>>> >>> >>> That will let UML itself against COMPILE_TEST (but all the other >>> architectures not). >>> >>> And if let COMPILE_TEST depend on !UML, can we still remove all >>> HAS_IOMEM and NO_IOMEM from kernel? (I guess so). >>> >>> If we can remove them, we can send related patch firstly -- that will >>> let current discussion be in UML architecture wide instead of kernel >>> wide. >>> >> >> Next, I shall: >> >> - Remove HAS_IOMEM and NO_IOMEM from kernel, firstly. > > This needs to be last, otherwise lot's of stuff will break. > OK, thanks, that sounds reasonable to me. >> - Try to make dummy IOMEM functions for score architecture. >> >> - Continue discussing with UML for it. > > If you find sane dummy functions for both UML and score I'm fine with it. > For me, what you said is necessary, tile and s390 also need dummy IOMEM when !PCI. So for me, I shall implement them in "include/asm-generic", and let uml, score, tile and s390 use dummy IOMEM when they need. Welcome any other members ideas, suggestions and completions. Thanks. -- Chen Gang Open share and attitude like air water and life which God blessed -- 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/