[PATCH] checkpatch: Fix false positive check for dt-binding docs and include

[Alex Tran <alex.t.tran@gmail.com>]

The check for when to display a DT_SPLIT_BINDING_PATCH warning
is performed on all files that are not MAINTAINERS files.
This causes issues, specifically when checking against a
patch that only touches docs/dt-bindings or a patch that
only touches include/dt-bindings. The warning is still
displayed when it should not be, giving false positives.

The check for when to issue a DT_SPLIT_BINDING_PATCH warning
is currently too pervasive and should only be performed when
a change under docs/dt-bindings is detected or include/dt-bindings.
If the current changed file is under include/dt-bindings or
docs/dt-bindings then it is compared to the last file detected
under include/dt-bindings or docs/dt-bindings. If there is a
difference then a warning is issued.

Signed-off-by: Alex Tran <alex.t.tran@gmail.com>
---
 scripts/checkpatch.pl | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c0250244cf7a3cb5e289b04fa4a9f644692dc278..fe3499bc9adda158c88231b48b3b0100f3af0ee1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2668,7 +2668,7 @@ sub process {
 	my $authorsignoff = 0;
 	my $author_sob = '';
 	my $is_patch = 0;
-	my $is_binding_patch = -1;
+	my $is_doc_binding_patch = -1;
 	my $in_header_lines = $file ? 0 : 1;
 	my $in_commit_log = 0;		#Scanning lines before patch
 	my $has_patch_separator = 0;	#Found a --- line
@@ -2924,13 +2924,13 @@ sub process {
 			}
 			$checklicenseline = 1;
 
-			if ($realfile !~ /^MAINTAINERS/) {
-				my $last_binding_patch = $is_binding_patch;
+			if ($realfile =~ m@^(?:Documentation/devicetree/|include/dt-bindings/)@) {
+				my $last_binding_patch_is_doc = $is_doc_binding_patch;
 
-				$is_binding_patch = () = $realfile =~ m@^(?:Documentation/devicetree/|include/dt-bindings/)@;
+				$is_doc_binding_patch = () = $realfile =~ m@^(?:Documentation/devicetree/)@;
 
-				if (($last_binding_patch != -1) &&
-				    ($last_binding_patch ^ $is_binding_patch)) {
+				if (($last_binding_patch_is_doc != -1) &&
+				    ($last_binding_patch_is_doc ^ $is_doc_binding_patch)) {
 					WARN("DT_SPLIT_BINDING_PATCH",
 					     "DT binding docs and includes should be a separate patch. See: Documentation/devicetree/bindings/submitting-patches.rst\n");
 				}

---
base-commit: fa084c35afa13ab07a860ef0936cd987f9aa0460
change-id: 20251224-checkscript_dt_bindings_fp-0e5938f6d274

Best regards,
-- 
Alex Tran <alex.t.tran@gmail.com>