on disabling drivers that use non-Free firmware

[Alexandre Oliva]

On Jan 25, 2009, Richard M Stallman <rms at gnu.org> wrote:

>    patch will report and error, ask questions and confuse users.
> Can we modify `patch' so that it doesn't annoy the user
> about patches to removed drivers.

No, that would be bad.  Patch is doing the right thing.

Patch could have an option for it to ignore patches to removed drivers,
but then we'd still have to modify documented procedures for applying
patches, and it still wouldn't solve the other problem:

>     Now, I'm not the only one affected by patch conflicts.

> I do not understand why you speak of "conflicts" in this context.
> What kind of "conflicts" result from deleting a file, and why, and how?

Consider a Makefile that says how to build a certain file, and that
lists that file as a dependency for some other file.

If we remove the source, the Makefile will fail, and the entire build
will fall over.

So, if we remove sources, we have to modify the Makefiles.  Once we do,
patches that mention that line as context, or that modify that line,
will fail to apply and require manual intervention.

> I do not know what Kconfig is, so I am unable to follow what you said
> about that.

Kconfig is a slight variation on this theme.  It specifies configuration
options and their interdependencies.

Currently, instead of modifying Makefiles, we disable the corresponding
configuration variables.  So, even when we remove a file, we won't run
into a build error, because the configuration option is forced disabled,
so the dependencies involving the missing or modified files will never
trigger.

However, Kconfig are also modified at times, and so the changes to it,
as small as they are today, still cause patch conflicts, i.e., cause
patches to fail to apply because the context is wrong.

-- 
Alexandre Oliva           http://www.lsd.ic.unicamp.br/~oliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer