docs: Raise the minimum Sphinx requirement to 2.4.4

Commit 31abfdda6527 (docs: Deprecate use of Sphinx < 2.4.x) in 6.2 added a
warning that support for older versions of Sphinx would be going away.
There have been no complaints, so the time has come. Raise the minimum
Sphinx version to 2.4.4 and clean out some compatibility code that we no
longer need.

Reviewed-by: Mauro Carvalho Chehab <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Corbet <[e-mail]>

Documentation/conf.py

···
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-needs_sphinx = '1.7'
+needs_sphinx = '2.4.4'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom

Documentation/doc-guide/sphinx.rst

···
 ==============
 
 The ReST markups currently used by the Documentation/ files are meant to be
-built with ``Sphinx`` version 1.7 or higher.
+built with ``Sphinx`` version 2.4.4 or higher.
 
 There's a script that checks for the Sphinx requirements. Please see
 :ref:`sphinx-pre-install` for further details.

Documentation/process/changes.rst

···
 iptables               1.4.2            iptables -V
 openssl & libcrypto    1.0.0            openssl version
 bc                     1.06.95          bc --version
-Sphinx\ [#f1]_         1.7              sphinx-build --version
+Sphinx\ [#f1]_         2.4.4            sphinx-build --version
 cpio                   any              cpio --version
 GNU tar                1.28             tar --version
 gtags (optional)       6.6.5            gtags --version

Documentation/sphinx/automarkup.py

···
 from docutils import nodes
 import sphinx
 from sphinx import addnodes
-if sphinx.version_info[0] < 2 or \
-   sphinx.version_info[0] == 2 and sphinx.version_info[1] < 1:
-    from sphinx.environment import NoUri
-else:
-    from sphinx.errors import NoUri
+from sphinx.errors import NoUri
 import re
 from itertools import chain
 

Documentation/sphinx/cdomain.py

···
 
     # Handle easy Sphinx 3.1+ simple new tags: :c:expr and .. c:namespace::
     app.connect('source-read', c_markups)
-
-    if (major == 1 and minor < 8):
-        app.override_domain(CDomain)
-    else:
-        app.add_domain(CDomain, override=True)
+    app.add_domain(CDomain, override=True)
 
     return dict(
         version = __version__,

Documentation/sphinx/kfigure.py

···
 from sphinx.util.nodes import clean_astext
 import kernellog
 
-# Get Sphinx version
-major, minor, patch = sphinx.version_info[:3]
-if major == 1 and minor > 3:
-    # patches.Figure only landed in Sphinx 1.4
-    from sphinx.directives.patches import Figure  # pylint: disable=C0413
-else:
-    Figure = images.Figure
+Figure = images.Figure
 
 __version__  = '1.0.0'
 

scripts/sphinx-pre-install

···
 my $activate_cmd;
 my $min_version;
 my $cur_version;
-my $rec_version = "1.7.9";	# PDF won't build here
-my $min_pdf_version = "2.4.4";	# Min version where pdf builds
+my $rec_version = "3.4.3";
 my $latest_avail_ver;
 
 #
···
 
 	# Version is OK. Nothing to do.
 	if ($cur_version && ($cur_version ge $rec_version)) {
-		if ($cur_version lt $min_pdf_version) {
-			print "note: If you want pdf, you need at least Sphinx $min_pdf_version.\n";
-		}
 		return;
 	};
 
···
 			printf "\nNeed to activate Sphinx (version $latest_avail_ver) on virtualenv with:\n";
 			printf "\t. $activate_cmd\n";
 			deactivate_help();
-
-			if ($latest_avail_ver lt $min_pdf_version) {
-				print "note: If you want pdf, you need at least Sphinx $min_pdf_version.\n";
-			}
 
 			return;
 		}