drm/amd/display: Add KUnit tests for amdgpu_dm_psr_set_event

[Why & How]
Add three KUnit tests covering the early-exit validation guard in
amdgpu_dm_psr_set_event():

  - NULL stream argument returns false immediately
  - Valid stream with NULL link returns false
  - Valid stream/link with psr_feature_enabled == false returns false

Assisted-by: Copilot:Claude-Sonnet-4.6
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 45 insertions, 6 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
index 4b823bba4392..dd26de9a57e5 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
@@ -25,6 +25,7 @@
  */
 
 #include "amdgpu_dm_psr.h"
+#include "amdgpu.h"
 #include "dc_dmub_srv.h"
 #include "dc.h"
 #include "amdgpu_dm.h"
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.h
index 9f3e22520ca0..40a09b5dc606 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.h
@@ -27,10 +27,12 @@
 #ifndef AMDGPU_DM_AMDGPU_DM_PSR_H_
 #define AMDGPU_DM_AMDGPU_DM_PSR_H_
 
-#include "amdgpu.h"
 #include "dc.h"
 #include "modules/inc/mod_power.h"
 
+struct amdgpu_display_manager;
+struct amdgpu_dm_connector;
+
 /* the number of pageflips before enabling psr */
 #define AMDGPU_DM_PSR_ENTRY_DELAY 5
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_psr_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_psr_test.c
index 61a4167898cb..09084f70a405 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_psr_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_psr_test.c
@@ -7,11 +7,7 @@
 
 #include <kunit/test.h>
 
-#include "dc.h"
-
-/* Extern declaration for the function under test */
-extern void amdgpu_dm_psr_fill_caps(struct dc_link *link,
-				     struct psr_caps *caps);
+#include "amdgpu_dm_psr.h"
 
 /*
  * Helper: allocate and zero-initialise a dc_link sufficient for
@@ -227,6 +223,43 @@ static void dm_test_psr_fill_caps_power_opts_z10_always_set(struct kunit *test)
 }
 /* End of tests for amdgpu_dm_psr_fill_caps() */
 
+/* Tests for amdgpu_dm_psr_set_event() — early-exit validation guards */
+
+static void dm_test_psr_set_event_null_stream(struct kunit *test)
+{
+	/* NULL stream → immediate false, dm is not accessed */
+	KUNIT_EXPECT_FALSE(test, amdgpu_dm_psr_set_event(NULL, NULL, true, psr_event_vsync, false));
+}
+
+static void dm_test_psr_set_event_null_link(struct kunit *test)
+{
+	struct dc_stream_state *stream;
+
+	stream = kunit_kzalloc(test, sizeof(*stream), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, stream);
+	/* stream->link remains NULL from kzalloc */
+
+	KUNIT_EXPECT_FALSE(test, amdgpu_dm_psr_set_event(NULL, stream, true, psr_event_vsync, false));
+}
+
+static void dm_test_psr_set_event_psr_not_enabled(struct kunit *test)
+{
+	struct dc_stream_state *stream;
+	struct dc_link *link;
+
+	stream = kunit_kzalloc(test, sizeof(*stream), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, stream);
+
+	link = kunit_kzalloc(test, sizeof(*link), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, link);
+
+	stream->link = link;
+	/* link->psr_settings.psr_feature_enabled remains false from kzalloc */
+
+	KUNIT_EXPECT_FALSE(test, amdgpu_dm_psr_set_event(NULL, stream, true, psr_event_vsync, false));
+}
+/* End of tests for amdgpu_dm_psr_set_event() */
+
 static struct kunit_case dm_psr_test_cases[] = {
 	KUNIT_CASE(dm_test_psr_fill_caps_version_1),
 	KUNIT_CASE(dm_test_psr_fill_caps_version_su1),
@@ -240,6 +273,9 @@ static struct kunit_case dm_psr_test_cases[] = {
 	KUNIT_CASE(dm_test_psr_fill_caps_dpcd_fields_unset),
 	KUNIT_CASE(dm_test_psr_fill_caps_rate_control_always_zero),
 	KUNIT_CASE(dm_test_psr_fill_caps_power_opts_z10_always_set),
+	KUNIT_CASE(dm_test_psr_set_event_null_stream),
+	KUNIT_CASE(dm_test_psr_set_event_null_link),
+	KUNIT_CASE(dm_test_psr_set_event_psr_not_enabled),
 	{}
 };