Messages in this thread | | | Date | Mon, 23 May 2016 11:03:14 -0700 | Subject | Re: [PATCH 1/4] isa: Allow ISA-style drivers on modern systems | From | Linus Torvalds <> |
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On Mon, May 23, 2016 at 7:58 AM, William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > > For now, the ISA_BUS Kconfig option is only be available on X86 > architectures. Support for other architectures may be added as required.
So I'd prefer to see that
> +config ISA_BUS_API > + def_bool ISA
part in arch/Kconfig.
Why?
Because other architectures _already_ define that ISA symbol, and we want the "ISA_BUS_API" to be a complete superset of ISA.
So whenever ISA is enabled, ISA_BUS_API should be enabled.
And the way you did that, that's not true. Now, if you were to enable ISA on ARM, you'd not get ISA_BUS_API. And that sounds insane to me. It also sounds *wrong* because it effectively changes the meaning of this:
--- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -10,7 +10,7 @@ obj-$(CONFIG_DMA_CMA) += dma-contiguous.o -obj-$(CONFIG_ISA) += isa.o +obj-$(CONFIG_ISA_BUS_API) += isa.o
where now that "isa.c" file gets built only on x86, whereas it *used* to get built whenever ISA was enabled.
So the reason I suggested a separate ISA_BUS_API config option (that then a particular architecture can choose to enable, in this case the x86 choice of selecting ISA_BUS) was _exactly_ this issue. The plain "ISA" config variable is not limited to x86, and the new subset of it (the ISA_BUS_API) thus also must not be limited to just x86.
Linus
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