[PATCH v3 3/5] drm/tests: Add test cases for drm_rect_calc_vscale()

[Arthur Grillo]

Insert parameterized test for the drm_rect_calc_vscale() to ensure
correctness and prevent future regressions. Besides the test for the
usual case, tests the exceptions.

It uses the same struct from drm_rect_calc_hscale().

Signed-off-by: Arthur Grillo <arthurgrillo at riseup.net>
---
 drivers/gpu/drm/tests/drm_rect_test.c | 59 +++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c
index 293e5c48bb32..30bb4d84f3a0 100644
--- a/drivers/gpu/drm/tests/drm_rect_test.c
+++ b/drivers/gpu/drm/tests/drm_rect_test.c
@@ -414,6 +414,64 @@ static void drm_test_rect_calc_hscale(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }
 
+static const struct drm_rect_scale_case drm_rect_vscale_cases[] = {
+	{
+		.name = "normal use",
+		.src = DRM_RECT_INIT(0, 0, 0, 2 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, 1 << 16),
+		.min_range = 0, .max_range = INT_MAX,
+		.expected_scaling_factor = 2,
+	},
+	{
+		.name = "out of max range",
+		.src = DRM_RECT_INIT(0, 0, 0, 10 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, 1 << 16),
+		.min_range = 3, .max_range = 5,
+		.expected_scaling_factor = -ERANGE,
+	},
+	{
+		.name = "out of min range",
+		.src = DRM_RECT_INIT(0, 0, 0, 2 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, 1 << 16),
+		.min_range = 3, .max_range = 5,
+		.expected_scaling_factor = -ERANGE,
+	},
+	{
+		.name = "zero dst height",
+		.src = DRM_RECT_INIT(0, 0, 0, 2 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, 0 << 16),
+		.min_range = 0, .max_range = INT_MAX,
+		.expected_scaling_factor = 0,
+	},
+	{
+		.name = "negative src height",
+		.src = DRM_RECT_INIT(0, 0, 0, -1 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, 1 << 16),
+		.min_range = 0, .max_range = INT_MAX,
+		.expected_scaling_factor = -EINVAL,
+	},
+	{
+		.name = "negative dst height",
+		.src = DRM_RECT_INIT(0, 0, 0, 1 << 16),
+		.dst = DRM_RECT_INIT(0, 0, 0, -1 << 16),
+		.min_range = 0, .max_range = INT_MAX,
+		.expected_scaling_factor = -EINVAL,
+	},
+};
+
+KUNIT_ARRAY_PARAM(drm_rect_vscale, drm_rect_vscale_cases, drm_rect_scale_case_desc);
+
+static void drm_test_rect_calc_vscale(struct kunit *test)
+{
+	const struct drm_rect_scale_case *params = test->param_value;
+	int scaling_factor;
+
+	scaling_factor = drm_rect_calc_vscale(&params->src, &params->dst,
+					      params->min_range, params->max_range);
+
+	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
+}
+
 static struct kunit_case drm_rect_tests[] = {
 	KUNIT_CASE(drm_test_rect_clip_scaled_div_by_zero),
 	KUNIT_CASE(drm_test_rect_clip_scaled_not_clipped),
@@ -421,6 +479,7 @@ static struct kunit_case drm_rect_tests[] = {
 	KUNIT_CASE(drm_test_rect_clip_scaled_signed_vs_unsigned),
 	KUNIT_CASE_PARAM(drm_test_rect_intersect, drm_rect_intersect_gen_params),
 	KUNIT_CASE_PARAM(drm_test_rect_calc_hscale, drm_rect_hscale_gen_params),
+	KUNIT_CASE_PARAM(drm_test_rect_calc_vscale, drm_rect_vscale_gen_params),
 	{ }
 };
 
-- 
2.39.2