[PATCH 30/49] drm/amd/display: Add KUnit tests for update_config

[Fangzhi Zuo <jerry.zuo@amd.com>]

From: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>

Expose update_config() for KUnit and cover the NULL connector and NULL
dc_link early returns, the dpms_off removal path and the active path
that builds the display/link state and registers the connector. The
active path leaves the DTM TA uninitialized so add_display_to_topology()
returns early without touching firmware.

Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_hdcp.c    |   4 +-
 .../amd/display/amdgpu_dm/amdgpu_dm_hdcp.h    |   1 +
 .../amdgpu_dm/tests/amdgpu_dm_hdcp_test.c     | 144 ++++++++++++++++++
 3 files changed, 148 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
index 7115cc0c7746..560bfa43dc8a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
@@ -606,7 +606,8 @@ bool enable_assr(void *handle, struct dc_link *link)
 }
 EXPORT_IF_KUNIT(enable_assr);
 
-static void update_config(void *handle, struct cp_psp_stream_config *config)
+STATIC_IFN_KUNIT
+void update_config(void *handle, struct cp_psp_stream_config *config)
 {
 	struct hdcp_workqueue *hdcp_work = handle;
 	struct amdgpu_dm_connector *aconnector;
@@ -692,6 +693,7 @@ static void update_config(void *handle, struct cp_psp_stream_config *config)
 	hdcp_w->aconnector[conn_index] = aconnector;
 	process_output(hdcp_w);
 }
+EXPORT_IF_KUNIT(update_config);
 
 /**
  * DOC: Add sysfs interface for set/get srm
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h
index b8ba2888a2ef..30c1e7b1af1a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h
@@ -124,6 +124,7 @@ void hdcp_remove_display(struct hdcp_workqueue *hdcp_work, unsigned int link_ind
 uint8_t *psp_get_srm(struct psp_context *psp, uint32_t *srm_version, uint32_t *srm_size);
 int psp_set_srm(struct psp_context *psp, u8 *srm, uint32_t srm_size, uint32_t *srm_version);
 bool enable_assr(void *handle, struct dc_link *link);
+void update_config(void *handle, struct cp_psp_stream_config *config);
 #endif
 
 #endif /* AMDGPU_DM_AMDGPU_DM_HDCP_H_ */
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_hdcp_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_hdcp_test.c
index 1580562727cd..b75fadd4e14e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_hdcp_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_hdcp_test.c
@@ -1580,6 +1580,145 @@ static void dm_test_enable_assr_initialized_builds_command_and_fails(struct kuni
 
 /* End of tests for enable_assr() */
 
+/* Tests for update_config() */
+
+/**
+ * dm_test_update_config_null_connector_is_noop - NULL stream ctx returns early
+ * @test: KUnit test context
+ *
+ * When config->dm_stream_ctx is NULL, update_config() must return before
+ * touching the workqueue, leaving the per-link aconnector array untouched.
+ */
+static void dm_test_update_config_null_connector_is_noop(struct kunit *test)
+{
+	struct hdcp_workqueue *work = alloc_test_workqueue_locked(test);
+	struct cp_psp_stream_config config = {0};
+
+	config.dm_stream_ctx = NULL;
+
+	update_config(work, &config);
+
+	KUNIT_EXPECT_PTR_EQ(test, work->aconnector[0], NULL);
+}
+
+/**
+ * dm_test_update_config_null_dc_link_is_noop - NULL dc_link returns early
+ * @test: KUnit test context
+ *
+ * A connector without a dc_link must cause update_config() to return before
+ * registering the connector, leaving the aconnector array untouched.
+ */
+static void dm_test_update_config_null_dc_link_is_noop(struct kunit *test)
+{
+	struct hdcp_workqueue *work = alloc_test_workqueue_locked(test);
+	struct amdgpu_dm_connector *aconnector;
+	struct cp_psp_stream_config config = {0};
+
+	aconnector = kunit_kzalloc(test, sizeof(*aconnector), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, aconnector);
+	aconnector->dc_link = NULL;
+
+	config.dm_stream_ctx = aconnector;
+
+	update_config(work, &config);
+
+	KUNIT_EXPECT_PTR_EQ(test, work->aconnector[0], NULL);
+}
+
+/**
+ * dm_test_update_config_dpms_off_removes_display - dpms_off path removes display
+ * @test: KUnit test context
+ *
+ * With config->dpms_off set, update_config() must take the removal path:
+ * hdcp_remove_display() reverts an ENABLED connector to DESIRED and clears
+ * its per-link aconnector entry.
+ */
+static void dm_test_update_config_dpms_off_removes_display(struct kunit *test)
+{
+	struct hdcp_workqueue *work = alloc_test_workqueue_locked(test);
+	struct amdgpu_dm_connector *aconnector = alloc_test_connector(test, 0);
+	struct drm_connector_state *conn_state;
+	struct cp_psp_stream_config config = {0};
+
+	conn_state = kunit_kzalloc(test, sizeof(*conn_state), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, conn_state);
+	conn_state->content_protection = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+	aconnector->base.state = conn_state;
+	work->aconnector[0] = aconnector;
+
+	config.dm_stream_ctx = aconnector;
+	config.dpms_off = true;
+
+	update_config(work, &config);
+
+	KUNIT_EXPECT_EQ(test, conn_state->content_protection,
+			DRM_MODE_CONTENT_PROTECTION_DESIRED);
+	KUNIT_EXPECT_PTR_EQ(test, work->aconnector[0], NULL);
+
+	cancel_delayed_work_sync(&work->property_validate_dwork);
+	cancel_delayed_work_sync(&work->callback_dwork);
+	cancel_delayed_work_sync(&work->watchdog_timer_dwork);
+}
+
+/**
+ * dm_test_update_config_populates_display_and_link - active path fills state
+ * @test: KUnit test context
+ *
+ * With dpms_off clear, update_config() must build the display and link from
+ * @config, reset the connector's encryption_status to HDCP_OFF, register the
+ * connector and reach process_output() (which enqueues property_validate).
+ *
+ * mod_hdcp_add_display() reaches add_display_to_topology(), which returns
+ * early because the DTM TA is left uninitialized, so no firmware is touched.
+ */
+static void dm_test_update_config_populates_display_and_link(struct kunit *test)
+{
+	struct hdcp_workqueue *work = alloc_test_workqueue_locked(test);
+	struct amdgpu_dm_connector *aconnector = alloc_test_connector(test, 0);
+	struct psp_context *psp;
+	struct cp_psp_stream_config config = {0};
+
+	/* add_display_to_topology() dereferences the psp handle. */
+	psp = kunit_kzalloc(test, sizeof(*psp), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, psp);
+	work->hdcp.config.psp.handle = psp;
+
+	config.dm_stream_ctx = aconnector;
+	config.dpms_off = false;
+	config.otg_inst = 1;
+	config.dig_fe = 4;
+	config.dig_be = 5;
+	config.stream_enc_idx = 6;
+	config.link_enc_idx = 7;
+	config.dio_output_idx = 8;
+	config.phy_idx = 2;
+
+	update_config(work, &config);
+
+	KUNIT_EXPECT_EQ(test, work->encryption_status[0],
+			MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF);
+	KUNIT_EXPECT_PTR_EQ(test, work->aconnector[0], aconnector);
+
+	KUNIT_EXPECT_EQ(test, work->display.state, MOD_HDCP_DISPLAY_ACTIVE);
+	KUNIT_EXPECT_EQ(test, work->display.controller,
+			CONTROLLER_ID_D0 + config.otg_inst);
+	KUNIT_EXPECT_EQ(test, work->display.dig_fe, config.dig_fe);
+	KUNIT_EXPECT_EQ(test, work->display.stream_enc_idx, config.stream_enc_idx);
+
+	KUNIT_EXPECT_EQ(test, work->link.dig_be, config.dig_be);
+	KUNIT_EXPECT_EQ(test, work->link.link_enc_idx, config.link_enc_idx);
+	KUNIT_EXPECT_EQ(test, work->link.dio_output_id, config.dio_output_idx);
+	KUNIT_EXPECT_EQ(test, work->link.phy_idx, config.phy_idx);
+
+	KUNIT_EXPECT_TRUE(test, work_pending(&work->property_validate_dwork.work));
+
+	cancel_delayed_work_sync(&work->property_validate_dwork);
+	cancel_delayed_work_sync(&work->callback_dwork);
+	cancel_delayed_work_sync(&work->watchdog_timer_dwork);
+}
+
+/* End of tests for update_config() */
+
 static struct kunit_case dm_hdcp_test_cases[] = {
 	/* hdcp_get_content_protection_from_status() */
 	KUNIT_CASE(dm_test_hdcp_get_cp_disabled_returns_desired),
@@ -1645,6 +1784,11 @@ static struct kunit_case dm_hdcp_test_cases[] = {
 	KUNIT_CASE(dm_test_enable_assr_uninitialized_dtm_returns_false),
 	KUNIT_CASE(dm_test_enable_assr_uninitialized_dtm_ignores_link),
 	KUNIT_CASE(dm_test_enable_assr_initialized_builds_command_and_fails),
+	/* update_config() */
+	KUNIT_CASE(dm_test_update_config_null_connector_is_noop),
+	KUNIT_CASE(dm_test_update_config_null_dc_link_is_noop),
+	KUNIT_CASE(dm_test_update_config_dpms_off_removes_display),
+	KUNIT_CASE(dm_test_update_config_populates_display_and_link),
 	{}
 };
 
-- 
2.53.0