Re: i2c: undefined option I2C_ALGO_BUSCLEAR

From: Valentin Rothberg
Date: Thu Nov 17 2016 - 12:46:41 EST


Hi Paul,

On Thu, Nov 17, 2016 at 12:55 PM, Paul Bolle <pebolle@xxxxxxxxxx> wrote:
> Hi Valentin,
>
> On Thu, 2016-11-17 at 12:33 +0100, Valentin Rothberg wrote:
>> I tested your patch and it works properly for me. It even still applies
>> on linux-next.
>
> Cool.
>
> (We should probably compile a list of current invalid selects somewhere
> publicly, and team up to submit patches for the low hanging fruit (ie, obvious
> typos) and for the arches that actually matter before I resubmit.)

Sounds like a plan. At the moment I really don't have much time, but
starting in mid December I could help. I propose to generate a bunch
of (rand)configs for different arches and collect the warnings with
your patch. After we just need to compare it with the symbols from
checkkconfigsymbols.

>> Would it be possible to extend your patch to also check
>> symbols in other statements (depends on, if, etc.)?
>
> No. Depending on an unknown symbol is common and correct. Think
> depends on SOME_OBSCURE_ARM_BOARD
>
> somewhere in drivers. Only arm builds will ever know about the
> SOME_OBSCURE_ARM_BOARD symbol.

You're completely right, thanks. Obviously I was too lazy to think about it.

> What could be done is starting any "make *config" target with a treewide pass
> over all Kconfig files to collect all valid symbols and so spot typos and
> other obviously incorrect. The example that comes to mind is
> depends on SH
>
> that I have spotted a few times in the past years. But this treewide pass will
> incur some runtime cost and might not be easy to implement cleanly. Perhaps
> we're better of with using your script for that.

I agree.

Kind regards,
Valentin