On 06/26/2013 06:17 PM, Richard Weinberger wrote: > Am 26.06.2013 12:01, schrieb Chen Gang: >> > On 06/26/2013 05:48 PM, Geert Uytterhoeven wrote: >>> >> On Wed, Jun 26, 2013 at 11:38 AM, Richard Weinberger <rich...@nod.at> >>> >> wrote: >>>>>>> >>>>>> Since the API itself already contents the meaning: "return NULL >>>>>>> >>>>>> means >>>>>>> >>>>>> the arch has no related io memory", >>> >> No, NULL means it could not map the I/O memory. >>> >> >> > >> > "it could not map the I/O memory" includes "has no related io memory". >> > So it is enough for our case. >> > >>>>>>> >>>>>> Why not define a generic dummy one in "include/asm-generic/io.h" >>>>>>> >>>>>> instead >>>>>>> >>>>>> of "HAS_IOMEM" (which has already spread many various places, >>>>>>> >>>>>> and also, >>>>>>> >>>>>> most of new drivers have to know about it). >>>>>>> >>>>>> >>>>>>> >>>>>> e.g: in "include/asm-generic/io.h", if "CONFIG_HAS_IOMEM=n", >>>>>>> >>>>>> define a >>>>>>> >>>>>> dummy ioremap() which return NULL ... (also need consider more >>>>>>> >>>>>> details). >>>>> >>>> >>>>> >>>> Because we don't even want to build these drivers and not make them >>>>> >>>> fail while >>>>> >>>> executing io memory related functions. >>> >> Indeed, it doesn't make sense to build drivers that cannot work. >>> >> And they may fail in a very bad way. >> > >> > That is our 'platform' guys feeling, not the 'module' guys, as >> > 'platform' guys, it is better to provide the choice to 'module' guys, >> > and let them decide by themselves, not forced by us. > FYI, this is my last reply to this thread. > > As Geert and I said, drivers which need io memory have to depend on > HAS_IOMEM=y. > If an arch does not have io memory these drivers cannot work and therefore we > don't > want them built.
It is really the time for stopping discussion, and thank you all for spending your time resources on this discussion. Next, I will send related patch for it (also cc to you all). Thanks. -- Chen Gang Asianux Corporation ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
