Why do some config options return limited info from a search?

[John Whitmore]

On Sun, Mar 18, 2018 at 08:49:52PM -0400, valdis.kletnieks at vt.edu wrote:
> On Mon, 19 Mar 2018 00:08:10 -0000, John Whitmore said:
> 
> > Sometimes however you get a module which don't give this information. Is this
> > intentional, signify something, or just an oversight for that config option?
> > For example SND_HDA_CORE:
> 
> > Symbol: SND_HDA_CORE [=m]
> >   Type  : tristate
> >   Defined at sound/hda/Kconfig:1
> >   Depends on: SOUND [=y] && !UML && SND [=y]
> >   Selects: REGMAP [=y]
> >   Selected by:
> >     - SND_HDA_EXT_CORE [=m] && SOUND [=y] && !UML && SND [=y]
> >     - SND_HDA [=m] && SOUND [=y] && !UML && SND [=y]
> 
> Some internal symbols don't have any visible menu-selects, because they are
> intended to be turned on only via other things doing 'SELECT'.  After all,
> SND_HDA_CORE has little to no reason to be enabled unless your kernel build
> config asks for SND_HDA or SND_HDA_EXT_CORE (and *that* symbol is 'm', which is
> why SND_HDA_CORE is also ''m'.  Switching EXT_CORE to 'y' will then auto-switch
> this one to 'y' as well).
> 

Perfectly logical and simple. Thanks for your answer that now all makes sense.