doc: update Kernel documentation build system

Update the docomentation build system according to Linux v5.11-rc1.

With this patch we can build the HTML documentation using either of
Sphinx 2 and Sphinx 3.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
[Fix warning in b4860qds.rst about "Switch Settings"]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/doc/sphinx/kerneldoc.py b/doc/sphinx/kerneldoc.py
index 4bcbd6a..e9857ab 100644
--- a/doc/sphinx/kerneldoc.py
+++ b/doc/sphinx/kerneldoc.py
@@ -62,6 +62,7 @@
         'export': directives.unchanged,
         'internal': directives.unchanged,
         'identifiers': directives.unchanged,
+        'no-identifiers': directives.unchanged,
         'functions': directives.unchanged,
     }
     has_content = False
@@ -70,6 +71,11 @@
         env = self.state.document.settings.env
         cmd = [env.config.kerneldoc_bin, '-rst', '-enable-lineno']
 
+	# Pass the version string to kernel-doc, as it needs to use a different
+	# dialect, depending what the C domain supports for each specific
+	# Sphinx versions
+        cmd += ['-sphinx-version', sphinx.__version__]
+
         filename = env.config.kerneldoc_srctree + '/' + self.arguments[0]
         export_file_patterns = []
 
@@ -99,6 +105,12 @@
             else:
                 cmd += ['-no-doc-sections']
 
+        if 'no-identifiers' in self.options:
+            no_identifiers = self.options.get('no-identifiers').split()
+            if no_identifiers:
+                for i in no_identifiers:
+                    cmd += ['-nosymbol', i]
+
         for pattern in export_file_patterns:
             for f in glob.glob(env.config.kerneldoc_srctree + '/' + pattern):
                 env.note_dependency(os.path.abspath(f))
@@ -136,7 +148,8 @@
                     lineoffset = int(match.group(1)) - 1
                     # we must eat our comments since the upset the markup
                 else:
-                    result.append(line, filename, lineoffset)
+                    doc = env.srcdir + "/" + env.docname + ":" + str(self.lineno)
+                    result.append(line, doc + ": " + filename, lineoffset)
                     lineoffset += 1
 
             node = nodes.section()