diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 74ff33c2ddaa51d5bec4e15e854a6f5dd9296139..b98bd7c5caeeba4f01b77227358539f644c8a539 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -404,6 +404,7 @@ static void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, unsigne
 
 	for (x = 0; x < pixels; x++) {
 		pix = le32_to_cpu(sbuf32[x]);
+		/* write blue-green-red to output in little endianness */
 		*dbuf8++ = (pix & 0x000000FF) >>  0;
 		*dbuf8++ = (pix & 0x0000FF00) >>  8;
 		*dbuf8++ = (pix & 0x00FF0000) >> 16;
diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 2191e57f22972b1dd2bf9553018be4d1a639a8e1..cd1d7da3483c1aedaddd783c7cc7686eff97267a 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -407,6 +407,10 @@ static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
 	iosys_map_set_vaddr(&src, xrgb8888);
 
+	/*
+	 * RGB888 expected results are already in little-endian
+	 * order, so there's no need to convert the test output.
+	 */
 	drm_fb_xrgb8888_to_rgb888(&dst, &result->dst_pitch, &src, &fb, &params->clip);
 	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
 }