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From: Grant Likely <grant.likely@secretlab.ca>
Date: Fri, 16 Jul 2010 14:17:05 -0600
Message-ID: <AANLkTimKpmZaGRYfYs8HGDz-_VG8ePXN6bZvl2-YcNdR@mail.gmail.com>
Subject: Re: [RFC PATCH] Kconfig: Enable Kconfig fragments to be used for
	defconfig
To: Catalin Marinas <catalin.marinas@arm.com>
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Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
	Daniel Walker <dwalker@codeaurora.org>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	linux-kbuild@vger.kernel.org, Tony Lindgren <tony@atomide.com>,
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On Fri, Jul 16, 2010 at 2:09 PM, Catalin Marinas
<catalin.marinas@arm.com> wrote:
> On Fri, 2010-07-16 at 19:46 +0100, Linus Torvalds wrote:
>> On Fri, Jul 16, 2010 at 11:40 AM, Nicolas Pitre <nico@fluxnic.net> wrote=
:
>> >
>> > DOH.
>>
>> Well, it's possible that the correct approach is a mixture.
>>
>> Automatically do the trivial cases (recursive selects, dependencies
>> that are simple or of the form "x && y" etc), and warn about the cases
>> that aren't trivial (where "not trivial" may not necessarily be about
>> fundamentally ambiguous ones, but just "complex enough that I won't
>> even try").
>
> There is still a risk with this approach when the Kconfig isn't entirely
> correct. For example, on ARM we have (I pushed a patch already):
>
> config CPU_32v6K
> =A0 =A0 =A0 =A0depends on CPU_V6
>
> config CPU_V7
> =A0 =A0 =A0 =A0select CPU_32v6K
>
> In this simple approach, we end up selecting CPU_V6 when we only need
> CPU_V7. There other places like this in the kernel.
>
> Of course, kbuild could still warn but if people rely on this feature to
> select options automatically I suspect they would ignore the warnings.

In my first patch, I made Kconfig problems errors instead of warnings.
 That would prevent people from ignoring them.

g.