Merge tag 'docs-4.15-2' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "A few late-arriving docs updates that have no real reason to wait.

  There's a new "Co-Developed-by" tag described by Greg, and a build
  enhancement from Willy to generate docs warnings during a kernel build
  (but only when additional warnings have been requested in general)"

* tag 'docs-4.15-2' of git://git.lwn.net/linux:
  Add optional check for bad kernel-doc comments
  Documentation: fix profile= options in kernel-parameters.txt
  documentation/svga.txt: update outdated file
  kokr/memory-barriers.txt: Fix typo in paring example
  kokr/memory-barriers/txt: Replace uses of "transitive"
  Documentation/process: add Co-Developed-by: tag for patches with multiple authors

scripts/kernel-doc

@@ -58,6 +58,7 @@ Output format selection (mutually exclusive):
   -man			Output troff manual page format. This is the default.
   -rst			Output reStructuredText format.
   -text			Output plain text format.
+  -none			Do not output documentation, only warnings.
 
 Output selection (mutually exclusive):
   -export		Only output documentation for symbols that have been
@@ -532,6 +533,8 @@ while ($ARGV[0] =~ m/^-(.*)/) {
 	$output_mode = "gnome";
 	@highlights = @highlights_gnome;
 	$blankline = $blankline_gnome;
+    } elsif ($cmd eq "-none") {
+	$output_mode = "none";
     } elsif ($cmd eq "-module") { # not needed for XML, inherits from calling document
 	$modulename = shift @ARGV;
     } elsif ($cmd eq "-function") { # to only output specific functions
@@ -2117,6 +2120,24 @@ sub output_blockhead_list(%) {
     }
 }
 
+
+## none mode output functions
+
+sub output_function_none(%) {
+}
+
+sub output_enum_none(%) {
+}
+
+sub output_typedef_none(%) {
+}
+
+sub output_struct_none(%) {
+}
+
+sub output_blockhead_none(%) {
+}
+
 ##
 # generic output function for all types (function, struct/union, typedef, enum);
 # calls the generated, variable output_ function name based on
@@ -3143,7 +3164,9 @@ sub process_file($) {
 	}
     }
     if ($initial_section_counter == $section_counter) {
-	print STDERR "${file}:1: warning: no structured comments found\n";
+	if ($output_mode ne "none") {
+	    print STDERR "${file}:1: warning: no structured comments found\n";
+	}
 	if (($output_selection == OUTPUT_INCLUDE) && ($show_not_found == 1)) {
 	    print STDERR "    Was looking for '$_'.\n" for keys %function_table;
 	}