From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Gang Subject: Re: [PATCH] drivers: Let several drivers depends on HAS_IOMEM for 'devm_ioremap_resource' Date: Sun, 20 Jul 2014 16:38:53 +0800 Message-ID: <53CB801D.1030603@gmail.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53C9612E.3040001@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: driverdev-devel-bounces@linuxdriverproject.org To: Lennox Wu Cc: linux-iio@vger.kernel.org, Benjamin Herrenschmidt , Tom Gundersen , Thierry Reding , Marek Vasut , Liqin Chen , Lars-Peter Clausen , Richard Weinberger , Geert Uytterhoeven , msalter@redhat.com, Guenter Roeck , linux-pwm@vger.kernel.org, devel@driverdev.osuosl.org, linux-watchdog@vger.kernel.org, Arnd Bergmann , linux-input@vger.kernel.org, Greg Kroah-Hartman , Dmitry Torokhov , "linux-kernel@vger.kernel.org" , knaack.h@gmx.de, Martin Schwidefsky , Mischa.Jonker@synopsys.com, jic23@kernel.org List-Id: linux-input@vger.kernel.org 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. - Try to make dummy IOMEM functions for score architecture. - Continue discussing with UML for it. By the way: how about HAS_DMA? can we treat it as HAS_IOMEM (remove it from kernel)? (for me, I guess we can not). At present, I shall finish sending patch for removing IOMEM today, and continue to welcome any ideas, suggestions or completions for IOMEM or DMA. Thanks. -- Chen Gang Open share and attitude like air water and life which God blessed