Re: [PATCH] docs: kbuild: remove ISDN references in Makefile examples

[Nicolas Schier <nsc@kernel.org>]

On Wed, Jun 17, 2026 at 08:18:51PM -0700, Nathan Chancellor wrote:
> On Sat, 13 Jun 2026 16:28:27 -0700, Ethan Nelson-Moore <enelsonmoore@gmail.com> wrote:
> > Documentation/kbuild/makefiles.rst uses some extracts from now-removed
> > ISDN code as examples. While they are harmless, they appeared in my
> > checks for CONFIG_* symbols referenced but not defined in the kernel.
> > Replace them with generic examples.
> 
> While I am fine with adjusting these examples to make it easier on tools
> such as yours, how does this solve your problem? CONFIG_FOO and
> CONFIG_BAR are still not defined anywhere. Are you adding exceptions for
> these symbols? I ask because I would like these to be a little more
> "kernel specific" if that makes sense.
> 
> Maybe it is not worth even checking Documentation/ for dead
> configurations at all since that is probably not going to be a bug very
> often but I guess it helps with cleaning up dead documentation?
> 
> >
> >
> > diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> > index 7521cae7d56f..ec8de1c20834 100644
> > --- a/Documentation/kbuild/makefiles.rst
> > +++ b/Documentation/kbuild/makefiles.rst
> > @@ -127,11 +127,8 @@ controllers are detected, and thus your disks are renumbered.
> >  
> >  Example::
> >  
> > -  #drivers/isdn/i4l/Makefile
> > -  # Makefile for the kernel ISDN subsystem and device drivers.
> > -  # Each configuration option enables a list of files.
> 
> I think I would keep these comment, it is still relevant (at least to
> me).
> 
> > -  obj-$(CONFIG_ISDN_I4L)         += isdn.o
> > -  obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
> > +  obj-$(CONFIG_FOO) += foo.o
> > +  obj-$(CONFIG_BAR) += bar.o
> 
> For instance, I think using a more descriptive symbol illustrates the
> example a little better.
> 
>   obj-$(CONFIG_DRIVER_ONE) += driver_one.o
>   obj-$(CONFIG_DRIVER_TWO) += driver_two.o
> 
> Same thing for the other examples. I just don't find these variable
> names to be particularly good when illustrating actual real world
> examples as opposed to conceptual ones. Not sure if others feel the same
> way.

+1

I liked that the examples were taken from actual Linux kconfigs, so it
was possible to look them up and check the context as well.  So, yes, I
think updating these is a good idea!

Kind regards,
Nicolas