On 07/20/2014 05:51 PM, Chen Gang wrote: > 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 <richard@xxxxxx>: >>>>>> 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. > > And sorry, I can not finish this discussion and send patch for it within this week, for it is really a long necessary discussion. But, hope we can finish this discussion and send patch for it within this month (but in current condition, I am not quite sure). And after finish discussion, welcome any other members help sending related patch for it (e.g. implement dummy IOMEM in "asm-generic", remove all IOMEM in kernel wide). 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-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
