[PATCH v2 3/6] drm/tests: Add KUnit tests for drm_fb_clip_offset()

[Arthur Grillo]

Insert parameterized test for the drm_fb_clip_offset() to ensure
correctness and prevent future regressions.

Signed-off-by: Arthur Grillo <arthurgri...@riseup.net>
Reviewed-by: Maíra Canal <mairaca...@riseup.net>
---
 drivers/gpu/drm/tests/drm_format_helper_test.c | 91 ++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c 
b/drivers/gpu/drm/tests/drm_format_helper_test.c
index d10e18fcb994..7f24da0b1e00 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -951,6 +951,96 @@ static void drm_test_fb_swab(struct kunit *test)
        KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
+struct clip_offset_case {
+       const char *name;
+       unsigned int pitch;
+       u32 format;
+       struct drm_rect clip;
+       unsigned int expected_offset;
+};
+
+static struct clip_offset_case clip_offset_cases[] = {
+       {
+               .name = "pass through",
+               .pitch = TEST_USE_DEFAULT_PITCH,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(0, 0, 3, 3),
+               .expected_offset = 0
+       },
+       {
+               .name = "horizontal offset",
+               .pitch = TEST_USE_DEFAULT_PITCH,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(1, 0, 3, 3),
+               .expected_offset = 4,
+       },
+       {
+               .name = "vertical offset",
+               .pitch = TEST_USE_DEFAULT_PITCH,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(0, 1, 3, 3),
+               .expected_offset = 12,
+       },
+       {
+               .name = "horizontal and vertical offset",
+               .pitch = TEST_USE_DEFAULT_PITCH,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(1, 1, 3, 3),
+               .expected_offset = 16,
+       },
+       {
+               .name = "horizontal offset (custom pitch)",
+               .pitch = 20,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(1, 0, 3, 3),
+               .expected_offset = 4,
+       },
+       {
+               .name = "vertical offset (custom pitch)",
+               .pitch = 20,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(0, 1, 3, 3),
+               .expected_offset = 20,
+       },
+       {
+               .name = "horizontal and vertical offset (custom pitch)",
+               .pitch = 20,
+               .format = DRM_FORMAT_XRGB8888,
+               .clip = DRM_RECT_INIT(1, 1, 3, 3),
+               .expected_offset = 24,
+       },
+};
+
+static void clip_offset_case_desc(struct clip_offset_case *t, char *desc)
+{
+       strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(clip_offset, clip_offset_cases, clip_offset_case_desc);
+
+static void drm_test_fb_clip_offset(struct kunit *test)
+{
+       const struct clip_offset_case *params = test->param_value;
+       const struct drm_format_info *format_info = 
drm_format_info(params->format);
+
+       unsigned int offset;
+       unsigned int pitch = params->pitch;
+
+       if (pitch == TEST_USE_DEFAULT_PITCH)
+               pitch = drm_format_info_min_pitch(format_info, 0,
+                                                 
drm_rect_width(&params->clip));
+
+       /*
+        * Assure that the pitch is not zero, because this will inevitable 
cause the
+        * wrong expected result
+        */
+       KUNIT_ASSERT_NE(test, pitch, 0);
+
+       offset = drm_fb_clip_offset(pitch, format_info, &params->clip);
+
+       KUNIT_EXPECT_EQ(test, offset, params->expected_offset);
+}
+
 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),
@@ -964,6 +1054,7 @@ static struct kunit_case drm_format_helper_test_cases[] = {
        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),
        KUNIT_CASE_PARAM(drm_test_fb_swab, convert_xrgb8888_gen_params),
+       KUNIT_CASE_PARAM(drm_test_fb_clip_offset, clip_offset_gen_params),
        {}
 };
 

-- 
2.41.0