Re: [PATCH v6] checkpatch.pl: Add SPDX license tag check

[Jonathan Corbet <corbet@lwn.net>]

On Fri, 2 Feb 2018 17:12:46 +0100
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> > What is the correct/acceptable license for documentation?
> > Creative Commons? AFAIK GPL is for source code.
> > 
> > Googling didn't bring the wished-for enlightenment.  
> 
> It depends on what you want to allow the documentation to be used for.
> It's not a simple answer :(

Honestly, GPL (or more permissive) is the only thing that really makes
sense.  Much of the documentation, once processed, includes an awful lot
of stuff directly from the kernel source; there's really no way to say
that it's not a derived product of the kernel.  So the output of "make
htmldocs" or "make pdfdocs" really has to be GPL, suggesting that the
input should be GPL-compatible.

GPL isn't the best license for documentation.  If we were starting today
I'd try to find a way to use CC-SA instead, but that's not where we're at.
And GPL is workable enough, I think.

At least that's how I see it, not that I really know any more than anybody
else.

jon