[PATCH 34/82] drm/amd/display: Cover hide_secondary_tile_from_userspace

From: Bhawanpreet Lakha <[email protected]>

Add a KUnit test that drives amdgpu_dm_connector_detect() through the
amdgpu_dm_hide_secondary_tile_from_userspace() path using a sink that
requests disable_second_tile and a synthesized DisplayID tiled EDID at a
non-origin tile location, so the secondary Apple Studio Display tile is
hidden and the connector reports disconnected. Raises the helper coverage
from 44% to 100%.

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Alex Hung <[email protected]>
Signed-off-by: Bhawanpreet Lakha <[email protected]>
Signed-off-by: Ivan Lipski <[email protected]>
---
 .../tests/amdgpu_dm_connector_test.c          | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c
index 1b1ed534ed441..55cf9c3708394 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c
@@ -4122,6 +4122,67 @@ static void dm_test_detect_no_sink(struct kunit *test)
 		(int)connector_status_disconnected);
 }
 
+/*
+ * A 256-byte EDID whose DisplayID extension carries a tiled display
+ * topology block placing this connector at tile location (h=1, v=0), i.e.
+ * a secondary tile. drm_edid_connector_update() parses it to set has_tile
+ * and the non-origin tile location.
+ */
+static const u8 dm_test_detect_tile_edid[256] = {
+	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x10, 0xac, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x04, 0x80, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xc4, 0x70, 0x12, 0x18, 0x00,
+	0x00, 0x12, 0x00, 0x15, 0x00, 0x11, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x8d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x90,
+};
+
+/**
+ * dm_test_detect_hides_secondary_tile - Test the secondary tile is hidden
+ * @test: The KUnit test context
+ *
+ * A sink whose panel patch requests disable_second_tile combined with a tiled
+ * EDID at a non-origin tile location makes the detect path hide the secondary
+ * Apple Studio Display tile, reporting the connector as disconnected.
+ */
+static void dm_test_detect_hides_secondary_tile(struct kunit *test)
+{
+	struct amdgpu_dm_connector *aconnector = dm_test_detect_connector(test);
+	struct dc_sink *sink;
+
+	sink = kunit_kzalloc(test, sizeof(*sink), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, sink);
+	sink->edid_caps.panel_patch.disable_second_tile = true;
+
+	aconnector->base.force = DRM_FORCE_UNSPECIFIED;
+	aconnector->dc_sink = sink;
+	aconnector->drm_edid = drm_edid_alloc(dm_test_detect_tile_edid,
+					     sizeof(dm_test_detect_tile_edid));
+	KUNIT_ASSERT_NOT_NULL(test, aconnector->drm_edid);
+
+	KUNIT_EXPECT_EQ(test,
+		(int)amdgpu_dm_connector_detect(&aconnector->base, false),
+		(int)connector_status_disconnected);
+
+	drm_edid_free(aconnector->drm_edid);
+}
+
 /* Tests for amdgpu_dm_connector_poll() */
 
 /**
@@ -6491,6 +6552,7 @@ static struct kunit_case amdgpu_dm_connector_tests[] = {
 	KUNIT_CASE(dm_test_detect_force_off),
 	KUNIT_CASE(dm_test_detect_sink_present),
 	KUNIT_CASE(dm_test_detect_no_sink),
+	KUNIT_CASE(dm_test_detect_hides_secondary_tile),
 	/* amdgpu_dm_connector_poll */
 	KUNIT_CASE(dm_test_poll_dac_load_returns_cached),
 	KUNIT_CASE(dm_test_poll_connected_cached_sink),
-- 
2.43.0