Re: [RFC PATCH] Input: tm2-touchkey - add hardware dependency

[Jean Delvare <jdelvare@suse.de>]

On Mon, 24 Apr 2017 11:58:09 +0200, Krzysztof Kozlowski wrote:
> On Mon, Apr 24, 2017 at 11:48 AM, Jean Delvare <jdelvare@suse.de> wrote:
> > On Mon, 24 Apr 2017 10:00:32 +0200, Krzysztof Kozlowski wrote:
> > > On Mon, Apr 24, 2017 at 9:42 AM, Jean Delvare <jdelvare@suse.de> wrote:
> > > > The tm2-touchkey driver is only useful on specific platforms. Add the
> > > > missing hardware dependency so that the driver is not proposed on
> > > > systems where the device does not exist.
> > >
> > > Although the device exists in only two upstreamed Exynos boards but
> > > there is no hardware dependency on Exynos. The hardware does not
> > > depend on Exynos.
> >
> > I understand that, and this is the reason why there was no dependency
> > expressed so far. But this is irrelevant to the problem I am trying to
> > solve, which is that people configuring a kernel for platforms where
> > this device is known to NOT exist shouldn't be bothered with a question
> > about its driver. This is what I meant with "hardware dependency" but
> > you can call it "hardware focus" or "intended hardware target" if you
> > prefer.
> 
> You need a depends-like version of "imply" keyword. I think it is
> worth adding it to solve such problems and help in configuring the
> system. However I am not convinced that "depends" should be used in
> the meaning of "intended use".

You are a bit late to the party I am afraid. COMPILE_TEST was
introduced for this very usage 4 years ago and I count 760 occurrences
of it. Not as many as I would like but I think this is going in the
right direction.

To be honest, I have also considered the possibility of a dedicated
keyword to express these "intended hardware target" soft dependencies.
Maybe it would make things clearer. But I never had the time to look
into it. Feel free to propose something if you are interested.

-- 
Jean Delvare
SUSE L3 Support