The builddir prefix was missing on make cleandocs. Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The PDF files that contain media images were actually generated
offline from their SVG or PNG source files.

Sphinx can handle PNG sources automatially. So, let's just
drop their PDF counterparts.

For SVG, however, Sphinx doesn't produce the right tags to
use the TexLive SVG support. Also, the SVG support is done via
shell execution, with is not nice.

So, while we don't have any support for SVG inside Sphinx
core or as an extension, move the logic to build them to Makefile,
producing the PDF images on runtime.

NOTE: due to the way Sphinx works, the PDF images should be
generated inside the Kernel source tree, as otherwise Sphinx
won't find it, not obeying what's specified by "O=" makefile
parameter.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add missing semicolon to fix pdf build with more than one SPHINXDIRS
directory specified. For example make SPHINXDIRS="gpu media" pdfdocs.

Fixes: cd21379b1698 ("doc-rst: generic way to build PDF of sub-folders")
Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Radically reduce the noise on stdout. The full build logs will still be
available under Documentatio/output/latex/*.log.

Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tested-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

With the unnecessary ; removed, the terminal URL detection also works
better.

Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Building latexdocs doesn't actually require $(PDFLATEX). Move the checks
for it to the pdfdocs target which does require it, and specifically
outside of the target in order to not depend on latexdocs when we can't
build pdfdocs anyway.

Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tested-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Refer to xelatex and latex options via variables. This allows the user
to override the pdflatex and latex options to use on the make command
line for experimenting. As a side effect, this makes the makefile a bit
tidier.

Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

This extends the method to build only sub-folders to the targets
"latexdocs" and "pdfdocs". To do so, a conf.py in the sub-folder is
required, where the latex_documents of the sub-folder are
defined. E.g. to build only gpu's PDF add the following to the
Documentation/gpu/conf.py::

  +latex_documents = [
  +    ("index", "gpu.tex", "Linux GPU Driver Developer's Guide",
  +     "The kernel development community", "manual"),
  +]

and run:

  make SPHINXDIRS=gpu pdfdocs

Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Sphinx supports LaTeX output. Sometimes, it is interesting to
call it directly, instead of also generating a PDF. As it comes
for free, add a target for it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

When building for LaTeX, it stops and enters into interactive
mode on errors. Don't do that, as there are some non-fatal errors
on media books when using Sphinx 1.4.x that we don't know how fix
yet.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>