On Wed, Jun 26, 2013 at 11:38 AM, Richard Weinberger <richard@xxxxxx> 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. >> 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. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html