[PATCH 09/70] drm/amd/display: add VBIOS bounding box KUnit test

[Wayne Lin <Wayne.Lin@amd.com>]

From: Alex Hung <alex.hung@amd.com>

[WHAT]
Add a KUnit test for dm_dmub_get_vbios_bounding_box() covering the
default IP-version path that returns NULL without allocating GPU memory
or issuing GPINT commands.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_dmub.c    |  3 ++-
 .../amd/display/amdgpu_dm/amdgpu_dm_dmub.h    |  1 +
 .../amdgpu_dm/tests/amdgpu_dm_dmub_test.c     | 24 +++++++++++++++++++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c
index 992d9f525ffc..21f6a01840ef 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c
@@ -385,7 +385,7 @@ dm_dmub_send_vbios_gpint_command(struct amdgpu_device *adev,
 	return DMUB_STATUS_TIMEOUT;
 }
 
-static void *dm_dmub_get_vbios_bounding_box(struct amdgpu_device *adev)
+STATIC_IFN_KUNIT void *dm_dmub_get_vbios_bounding_box(struct amdgpu_device *adev)
 {
 	void *bb;
 	long long addr;
@@ -440,6 +440,7 @@ static void *dm_dmub_get_vbios_bounding_box(struct amdgpu_device *adev)
 	return NULL;
 
 }
+EXPORT_IF_KUNIT(dm_dmub_get_vbios_bounding_box);
 
 enum dmub_ips_disable_type dm_get_default_ips_mode(
 	struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.h
index ba50e1af80c1..c53728d1c131 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.h
@@ -69,6 +69,7 @@ int dm_init_microcode(struct amdgpu_device *adev);
 struct dc_context;
 struct dmub_cmd_fused_request;
 
+void *dm_dmub_get_vbios_bounding_box(struct amdgpu_device *adev);
 void abort_fused_io(struct dc_context *ctx,
 		    const struct dmub_cmd_fused_request *request);
 #endif
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c
index d75ee1c930ee..ead43eeb38c7 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c
@@ -932,6 +932,28 @@ static void dm_test_init_microcode_unsupported_asic(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, dm_init_microcode(adev), 0);
 }
 
+/* Tests for dm_dmub_get_vbios_bounding_box() */
+
+/**
+ * dm_test_dmub_get_vbios_bounding_box_default_null - Test default IP version returns NULL
+ * @test: The KUnit test context
+ *
+ * For an IP version without a bounding-box size mapping, the switch falls
+ * through to the default case and dm_dmub_get_vbios_bounding_box() returns
+ * NULL without allocating GPU memory or issuing GPINT commands.
+ */
+static void dm_test_dmub_get_vbios_bounding_box_default_null(struct kunit *test)
+{
+	struct amdgpu_device *adev;
+
+	adev = kunit_kzalloc(test, sizeof(*adev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, adev);
+
+	adev->ip_versions[DCE_HWIP][0] = IP_VERSION(3, 5, 0);
+
+	KUNIT_EXPECT_NULL(test, dm_dmub_get_vbios_bounding_box(adev));
+}
+
 /* Tests for dm_execute_dmub_cmd() */
 
 /**
@@ -1369,6 +1391,8 @@ static struct kunit_case amdgpu_dm_dmub_tests[] = {
 	KUNIT_CASE(dm_test_dmub_sw_init_unsupported_asic),
 	/* dm_init_microcode() */
 	KUNIT_CASE(dm_test_init_microcode_unsupported_asic),
+	/* dm_dmub_get_vbios_bounding_box() */
+	KUNIT_CASE(dm_test_dmub_get_vbios_bounding_box_default_null),
 	/* dm_execute_dmub_cmd() */
 	KUNIT_CASE(dm_test_execute_dmub_cmd_null_dmub_srv),
 	/* amdgpu_dm_process_dmub_aux_transfer_sync() */
-- 
2.43.0