[PATCH v5 0/3] KUnit tests for RGB888, XRGB2101010 and grayscale

[PATCH v5 0/3] KUnit tests for RGB888, XRGB2101010 and grayscale

[José Expósito]

Hello everyone,

This series is a follow up on my work adding KUnit test to the XRGB8888
conversion functions. This time RGB888, XRGB2101010 and gray8 are added.

Best wishes,
Jose

v1 -> v2:

    Tested-by: Maíra Canal <mairacanal@riseup.net>
    Reviewed-by: David Gow <davidgow@google.com>

v2 -> v3:

    Export symbol drm_fb_xrgb8888_to_xrgb2101010()

v3 -> v4:

    Rebased on top of Maíra's prefix renaming work:
    https://lore.kernel.org/dri-devel/20220911191756.203118-1-mairacanal@riseup.net/T/

v4 -> v5:

    Acked-by: Maxime Ripard <maxime@cerno.tech>
    Remove reduntant "_test" suffix
    Sort test alphabetically

José Expósito (3):
  drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb888()
  drm/format-helper: Add KUnit tests for
    drm_fb_xrgb8888_to_xrgb2101010()
  drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_gray8()

 drivers/gpu/drm/drm_format_helper.c           |   1 +
 .../gpu/drm/tests/drm_format_helper_test.c    | 190 ++++++++++++++++++
 2 files changed, 191 insertions(+)


base-commit: 961bcdf956a4645745407a5d919be8757549b062
prerequisite-patch-id: 605f4eb1bbdb8ed39cb2ebed95768d922486099f
prerequisite-patch-id: 3818f7fa7c81927c8a88607c4955a45d614ee69a
prerequisite-patch-id: 634952f085f249f2e18893a3f8344a2ff27c13ad
prerequisite-patch-id: fe7ea3dd385fe6c64d7c5c8d65ebe6f9c7ab047b
prerequisite-patch-id: c92ac7a03faee6e1000637928628e7fd127d0159
prerequisite-patch-id: f52fbd427e8730c62b5554f68713e6fa742ffcab
prerequisite-patch-id: 1a2dc68fd107316fd1d1bb91376fe19bdb039147
prerequisite-patch-id: d91c951338cfe9f06e8b8aa74856f6dc08ac8212
prerequisite-patch-id: 41a65e680affc8011670762aec58c373030ef4ea
prerequisite-patch-id: bbd5bf45c2185a9f2a551447247ce13f81df7c2a
prerequisite-patch-id: 9802d5e3291f150a9ceba345628bbf04be972aba
prerequisite-patch-id: 0bae228d241c6c5567c0b58fa4447a3bcb35d5f2
prerequisite-patch-id: e2ed4b2c89623279d2201a81259b49ce56c5bb38
prerequisite-patch-id: 57b3203672cf7617dc1d63d3eb1373e3b2b7ca34
prerequisite-patch-id: 85c127f8e3d55e4210a00d5c84e2c4f92e2e16ad
prerequisite-patch-id: cad729f2d039e636d2f3f937a9f26b1fb4455388
prerequisite-patch-id: c9e696a62ea5f2d4407914ff7a8371e285f33d55
prerequisite-patch-id: 08f30e5572d2e5a8153b563dd4d8fa0ece2cc575
prerequisite-patch-id: c7f7be4f8e90e5eb473a82c293a6b6a0f417e2ba
prerequisite-patch-id: b0c636c391f5d0ebb50a07222f3e41f48cab8c76
prerequisite-patch-id: 705cc9ff7eb3e3e2873cfdb68c2d2272fde38baf
prerequisite-patch-id: cfbe2b5cbfd69cf9f0b11c7c329cf8ec5a2ecff4
prerequisite-patch-id: e7df3b6bbfb6bb87efaf39e73f2e4ed1f83558af
prerequisite-patch-id: 554f79bc7984201131876865f5c1765c20f84ab5
prerequisite-patch-id: 3b848305159028d4b7e1dd9013050aba60f0ca41
prerequisite-patch-id: 9e9b33181259f59bf03f1fe9b3ef1d6160ae89d9
prerequisite-patch-id: 9aefed850bf64f9015299473087fadf015d246eb
prerequisite-patch-id: 3f886741cdfeff02432de1b0f5ed9d25a2847576
prerequisite-patch-id: 3e81b7138067f19ee34bd7a418c01444979ccab3
prerequisite-patch-id: 59d64b331417360de507c782fc7c33af1ac6dfc3
prerequisite-patch-id: 8b35c6be1c70eaabcd1644a38731139f5be3153a
prerequisite-patch-id: d0008bddf1653ff2452f349b018eaeb3bbcae698
prerequisite-patch-id: dc45c65927286ed6da022ffae1f861cd74efe89d
prerequisite-patch-id: 79665be026f637db6b4ab52cb6cebfb0406c5bb8
prerequisite-patch-id: df37cbcb0f8716cf806910c742bbca83574bee00
prerequisite-patch-id: ea87b84377d7878f9608166731cdbd5acfa0d44b
prerequisite-patch-id: 0158c508dd88a47c2a241a144c73b197bc84a533
prerequisite-patch-id: efbf15a64e673484a4d3187596f2c913e726ef1a
prerequisite-patch-id: 920ebf96ab5fda37dcabd5febf6d8b4123fa141b
prerequisite-patch-id: 8bb836f74b1a7fdc5352ad53eedaa763815a3e04
prerequisite-patch-id: 04c88d73e6c470f9e31864c0a5cd5b3307c54417
prerequisite-patch-id: 55cf446abf46692670cf6591fb3f012e6aeb256b
prerequisite-patch-id: f28093a62972e0106b15128241fd4946e0c25cd9
prerequisite-patch-id: e9c3e896c6d3d8199abca3a2d4f852ee6f8b6539
prerequisite-patch-id: 588661d6d23181fc73748ae49699990fb003d3ee
prerequisite-patch-id: 3edb549d3f36417d929da4be9a0da15c325c8ab7
prerequisite-patch-id: 7897a7b1e3ec3fd588dc4788bbff4bb399683b1e
prerequisite-patch-id: 05f5209e92385701c23665d7825c4d00a1abfd72
prerequisite-patch-id: 634075ca9541a14809bdef5df8c9240134773117
prerequisite-patch-id: 1cfe8abd19e3b8ab5d2ba30991ff5366dedf16db
prerequisite-patch-id: 831a7a6cf76aa3bd41af7764113c48749e40431d
-- 
2.25.1

[PATCH v5 1/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb888()

[José Expósito]

Extend the existing test cases to test the conversion from XRGB8888 to
RGB888.

Tested-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 .../gpu/drm/tests/drm_format_helper_test.c    | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index ab49f5e8796c..bc830601e7a2 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -27,6 +27,11 @@ struct convert_to_rgb565_result {
 	const u16 expected_swab[TEST_BUF_SIZE];
 };
 
+struct convert_to_rgb888_result {
+	unsigned int dst_pitch;
+	const u8 expected[TEST_BUF_SIZE];
+};
+
 struct convert_xrgb8888_case {
 	const char *name;
 	unsigned int pitch;
@@ -34,6 +39,7 @@ struct convert_xrgb8888_case {
 	const u32 xrgb8888[TEST_BUF_SIZE];
 	struct convert_to_rgb332_result rgb332_result;
 	struct convert_to_rgb565_result rgb565_result;
+	struct convert_to_rgb888_result rgb888_result;
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -51,6 +57,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.expected = { 0xF800 },
 			.expected_swab = { 0x00F8 },
 		},
+		.rgb888_result = {
+			.dst_pitch = 0,
+			.expected = { 0x00, 0x00, 0xFF },
+		},
 	},
 	{
 		.name = "single_pixel_clip_rectangle",
@@ -69,6 +79,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.expected = { 0xF800 },
 			.expected_swab = { 0x00F8 },
 		},
+		.rgb888_result = {
+			.dst_pitch = 0,
+			.expected = { 0x00, 0x00, 0xFF },
+		},
 	},
 	{
 		/* Well known colors: White, black, red, green, blue, magenta,
@@ -109,6 +123,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0xE0FF, 0xFF07,
 			},
 		},
+		.rgb888_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0xFF, 0x00, 0xFF, 0x00,
+				0xFF, 0x00, 0x00, 0xFF, 0x00, 0xFF,
+				0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00,
+			},
+		},
 	},
 	{
 		/* Randomly picked colors. Full buffer within the clip area. */
@@ -141,6 +164,17 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x00A8, 0x8E6B, 0x330A, 0x0000, 0x0000,
 			},
 		},
+		.rgb888_result = {
+			.dst_pitch = 15,
+			.expected = {
+				0x9C, 0x44, 0x0E, 0x05, 0x4D, 0x11, 0x03, 0x03, 0xA8,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x73, 0x70, 0x6C, 0x9C, 0x44, 0x0E, 0x05, 0x4D, 0x11,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x03, 0x03, 0xA8, 0x73, 0x70, 0x6C, 0x9C, 0x44, 0x0E,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+		},
 	},
 };
 
@@ -255,9 +289,40 @@ static void drm_test_fb_xrgb8888_to_rgb565(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected_swab, dst_size), 0);
 }
 
+static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_rgb888_result *result = &params->rgb888_result;
+	size_t dst_size;
+	__u8 *buf = NULL;
+	__u32 *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(DRM_FORMAT_RGB888, 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 = le32buf_to_cpu(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_rgb888(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+}
+
 static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb332, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb565, convert_xrgb8888_gen_params),
+	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb888, convert_xrgb8888_gen_params),
 	{}
 };
 
-- 
2.25.1

[PATCH v5 2/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_xrgb2101010()

[José Expósito]

Extend the existing test cases to test the conversion from XRGB8888 to
XRGB2101010.

In order to be able to call drm_fb_xrgb8888_to_xrgb2101010() when
compiling CONFIG_DRM_KMS_HELPER as a module export the symbol.

Tested-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 drivers/gpu/drm/drm_format_helper.c           |  1 +
 .../gpu/drm/tests/drm_format_helper_test.c    | 63 +++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 4afc4ac27342..e2f76621453c 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -553,6 +553,7 @@ void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *d
 	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
 		    drm_fb_xrgb8888_to_xrgb2101010_line);
 }
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
 
 static void drm_fb_xrgb8888_to_gray8_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index bc830601e7a2..4a2f3c0de060 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -32,6 +32,11 @@ struct convert_to_rgb888_result {
 	const u8 expected[TEST_BUF_SIZE];
 };
 
+struct convert_to_xrgb2101010_result {
+	unsigned int dst_pitch;
+	const u32 expected[TEST_BUF_SIZE];
+};
+
 struct convert_xrgb8888_case {
 	const char *name;
 	unsigned int pitch;
@@ -40,6 +45,7 @@ struct convert_xrgb8888_case {
 	struct convert_to_rgb332_result rgb332_result;
 	struct convert_to_rgb565_result rgb565_result;
 	struct convert_to_rgb888_result rgb888_result;
+	struct convert_to_xrgb2101010_result xrgb2101010_result;
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -61,6 +67,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x00, 0x00, 0xFF },
 		},
+		.xrgb2101010_result = {
+			.dst_pitch = 0,
+			.expected = { 0x3FF00000 },
+		},
 	},
 	{
 		.name = "single_pixel_clip_rectangle",
@@ -83,6 +93,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x00, 0x00, 0xFF },
 		},
+		.xrgb2101010_result = {
+			.dst_pitch = 0,
+			.expected = { 0x3FF00000 },
+		},
 	},
 	{
 		/* Well known colors: White, black, red, green, blue, magenta,
@@ -132,6 +146,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00,
 			},
 		},
+		.xrgb2101010_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0x3FFFFFFF, 0x00000000,
+				0x3FF00000, 0x000FFC00,
+				0x000003FF, 0x3FF003FF,
+				0x3FFFFC00, 0x000FFFFF,
+			},
+		},
 	},
 	{
 		/* Randomly picked colors. Full buffer within the clip area. */
@@ -175,6 +198,14 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			},
 		},
+		.xrgb2101010_result = {
+			.dst_pitch = 20,
+			.expected = {
+				0x03844672, 0x0444D414, 0x2A20300C, 0x00000000, 0x00000000,
+				0x1B1705CD, 0x03844672, 0x0444D414, 0x00000000, 0x00000000,
+				0x2A20300C, 0x1B1705CD, 0x03844672, 0x00000000, 0x00000000,
+			},
+		},
 	},
 };
 
@@ -319,10 +350,42 @@ static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
 }
 
+static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_xrgb2101010_result *result = &params->xrgb2101010_result;
+	size_t dst_size;
+	__u32 *buf = NULL;
+	__u32 *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(DRM_FORMAT_XRGB2101010,
+				       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 = le32buf_to_cpu(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_xrgb2101010(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	buf = le32buf_to_cpu(test, buf, TEST_BUF_SIZE);
+	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+}
+
 static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb332, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb565, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb888, convert_xrgb8888_gen_params),
+	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_xrgb2101010, convert_xrgb8888_gen_params),
 	{}
 };
 
-- 
2.25.1

[PATCH v5 3/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_gray8()

[José Expósito]

Extend the existing test cases to test the conversion from XRGB8888 to
grayscale.

Tested-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 .../gpu/drm/tests/drm_format_helper_test.c    | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 4a2f3c0de060..8d86c250c2ec 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -16,6 +16,11 @@
 
 #define TEST_BUF_SIZE 50
 
+struct convert_to_gray8_result {
+	unsigned int dst_pitch;
+	const u8 expected[TEST_BUF_SIZE];
+};
+
 struct convert_to_rgb332_result {
 	unsigned int dst_pitch;
 	const u8 expected[TEST_BUF_SIZE];
@@ -42,6 +47,7 @@ struct convert_xrgb8888_case {
 	unsigned int pitch;
 	struct drm_rect clip;
 	const u32 xrgb8888[TEST_BUF_SIZE];
+	struct convert_to_gray8_result gray8_result;
 	struct convert_to_rgb332_result rgb332_result;
 	struct convert_to_rgb565_result rgb565_result;
 	struct convert_to_rgb888_result rgb888_result;
@@ -54,6 +60,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 		.pitch = 1 * 4,
 		.clip = DRM_RECT_INIT(0, 0, 1, 1),
 		.xrgb8888 = { 0x01FF0000 },
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = { 0x4C },
+		},
 		.rgb332_result = {
 			.dst_pitch = 0,
 			.expected = { 0xE0 },
@@ -80,6 +90,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			0x00000000, 0x00000000,
 			0x00000000, 0x10FF0000,
 		},
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = { 0x4C },
+		},
 		.rgb332_result = {
 			.dst_pitch = 0,
 			.expected = { 0xE0 },
@@ -113,6 +127,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			0x00000000, 0x550000FF, 0x66FF00FF, 0x00000000,
 			0x00000000, 0x77FFFF00, 0x8800FFFF, 0x00000000,
 		},
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0xFF, 0x00,
+				0x4C, 0x99,
+				0x19, 0x66,
+				0xE5, 0xB2,
+			},
+		},
 		.rgb332_result = {
 			.dst_pitch = 0,
 			.expected = {
@@ -166,6 +189,14 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			0xD16C7073, 0xA20E449C, 0xB2114D05,
 			0xC2A80303, 0xD26C7073, 0xA30E449C,
 		},
+		.gray8_result = {
+			.dst_pitch = 5,
+			.expected = {
+				0x3C, 0x33, 0x34, 0x00, 0x00,
+				0x6F, 0x3C, 0x33, 0x00, 0x00,
+				0x34, 0x6F, 0x3C, 0x00, 0x00,
+			},
+		},
 		.rgb332_result = {
 			.dst_pitch = 5,
 			.expected = {
@@ -257,6 +288,36 @@ static void convert_xrgb8888_case_desc(struct convert_xrgb8888_case *t,
 KUNIT_ARRAY_PARAM(convert_xrgb8888, convert_xrgb8888_cases,
 		  convert_xrgb8888_case_desc);
 
+static void drm_test_fb_xrgb8888_to_gray8(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_gray8_result *result = &params->gray8_result;
+	size_t dst_size;
+	__u8 *buf = NULL;
+	__u32 *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(DRM_FORMAT_R8, 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 = le32buf_to_cpu(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_gray8(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+}
+
 static void drm_test_fb_xrgb8888_to_rgb332(struct kunit *test)
 {
 	const struct convert_xrgb8888_case *params = test->param_value;
@@ -382,6 +443,7 @@ static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test)
 }
 
 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),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb565, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb888, convert_xrgb8888_gen_params),
-- 
2.25.1