diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 9536829c6e3a..0610341e7349 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -67,6 +67,11 @@ struct convert_to_argb2101010_result {
 	const u32 expected[TEST_BUF_SIZE];
 };
 
+struct convert_to_mono_result {
+	unsigned int dst_pitch;
+	const u8 expected[TEST_BUF_SIZE];
+};
+
 struct convert_xrgb8888_case {
 	const char *name;
 	unsigned int pitch;
@@ -82,6 +87,7 @@ struct convert_xrgb8888_case {
 	struct convert_to_argb8888_result argb8888_result;
 	struct convert_to_xrgb2101010_result xrgb2101010_result;
 	struct convert_to_argb2101010_result argb2101010_result;
+	struct convert_to_mono_result mono_result;
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -131,6 +137,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0xFFF00000 },
 		},
+		.mono_result = {
+			.dst_pitch = 0,
+			.expected = { 0x00 },
+		},
 	},
 	{
 		.name = "single_pixel_clip_rectangle",
@@ -181,6 +191,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0xFFF00000 },
 		},
+		.mono_result = {
+			.dst_pitch = 0,
+			.expected = { 0x00 },
+		},
 	},
 	{
 		/* Well known colors: White, black, red, green, blue, magenta,
@@ -293,6 +307,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0xFFFFFC00, 0xC00FFFFF,
 			},
 		},
+		.mono_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0x01,
+				0x02,
+				0x00,
+				0x03,
+			},
+		},
 	},
 	{
 		/* Randomly picked colors. Full buffer within the clip area. */
@@ -392,6 +415,14 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0xEA20300C, 0xDB1705CD, 0xC3844672, 0x00000000, 0x00000000,
 			},
 		},
+		.mono_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0x00,
+				0x00,
+				0x00,
+			},
+		},
 	},
 };
 
@@ -419,6 +450,17 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
 	return dst_pitch * drm_rect_height(clip);
 }
 
+static size_t conversion_buf_size_mono(unsigned int dst_pitch, const struct drm_rect *clip)
+{
+	if (!dst_pitch) {
+		unsigned int linepixels = drm_rect_width(clip) * 1;
+
+		dst_pitch = DIV_ROUND_UP(linepixels, 8);
+	}
+
+	return dst_pitch * drm_rect_height(clip);
+}
+
 static u16 *le16buf_to_cpu(struct kunit *test, const __le16 *buf, size_t buf_size)
 {
 	u16 *dst = NULL;
@@ -789,6 +831,36 @@ static void drm_test_fb_xrgb8888_to_argb2101010(struct kunit *test)
 	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
+static void drm_test_fb_xrgb8888_to_mono(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_mono_result *result = &params->mono_result;
+	size_t dst_size;
+	u8 *buf = NULL;
+	__le32 *xrgb8888 = NULL;
+	struct iosys_map dst, src;
+
+	struct drm_framebuffer fb = {
+		.format = drm_format_info(DRM_FORMAT_XRGB8888),
+		.pitches = { params->pitch, 0, 0 },
+	};
+
+	dst_size = conversion_buf_size_mono(result->dst_pitch, &params->clip);
+
+	KUNIT_ASSERT_GT(test, dst_size, 0);
+
+	buf = kunit_kzalloc(test, dst_size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);
+	iosys_map_set_vaddr(&dst, buf);
+
+	xrgb8888 = cpubuf_to_le32(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_mono(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
+}
+
 static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_gray8, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb332, convert_xrgb8888_gen_params),
@@ -800,6 +872,7 @@ static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_argb8888, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_xrgb2101010, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_argb2101010, convert_xrgb8888_gen_params),
+	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_mono, convert_xrgb8888_gen_params),
 	{}
 };
 
