[PATCH 07/34] drm/amd/display: Add amdgpu_dm_crtc_late_register test

From: Bhawanpreet Lakha <[email protected]>

why:
amdgpu_dm_crtc_late_register wires up the CRTC debugfs entries during
registration but had no coverage, leaving its single path untested.

how:
Expose amdgpu_dm_crtc_late_register for KUnit via STATIC_IFN_KUNIT and
EXPORT_IF_KUNIT (guarded by CONFIG_DEBUG_FS) and declare it in the KUnit
header block. Add dm_test_crtc_late_register_inits_debugfs, which gives
the CRTC a real debugfs parent, calls the callback, verifies it returns 0,
and tears down the debugfs directory.

Reviewed-by: Alex Hung <[email protected]>
Signed-off-by: Bhawanpreet Lakha <[email protected]>
Signed-off-by: Tom Chung <[email protected]>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_crtc.c    |  3 +-
 .../amd/display/amdgpu_dm/amdgpu_dm_crtc.h    |  3 ++
 .../amdgpu_dm/tests/amdgpu_dm_crtc_test.c     | 32 +++++++++++++++++++
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
index 470abe9cc8f1..abe0769ed502 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
@@ -488,12 +488,13 @@ STATIC_IFN_KUNIT void amdgpu_dm_crtc_reset_state(struct drm_crtc *crtc)
 EXPORT_IF_KUNIT(amdgpu_dm_crtc_reset_state);
 
 #ifdef CONFIG_DEBUG_FS
-static int amdgpu_dm_crtc_late_register(struct drm_crtc *crtc)
+STATIC_IFN_KUNIT int amdgpu_dm_crtc_late_register(struct drm_crtc *crtc)
 {
 	crtc_debugfs_init(crtc);
 
 	return 0;
 }
+EXPORT_IF_KUNIT(amdgpu_dm_crtc_late_register);
 #endif
 
 #ifdef AMD_PRIVATE_COLOR
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.h
index 06bb22d4c3b7..a2b105a496e0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.h
@@ -56,6 +56,9 @@ void amdgpu_dm_crtc_update_crtc_active_planes(struct drm_crtc *crtc,
 					      struct drm_crtc_state *new_crtc_state);
 void amdgpu_dm_crtc_vblank_control_worker(struct work_struct *work);
 void amdgpu_dm_idle_worker(struct work_struct *work);
+#ifdef CONFIG_DEBUG_FS
+int amdgpu_dm_crtc_late_register(struct drm_crtc *crtc);
+#endif
 #endif
 
 bool amdgpu_dm_crtc_vrr_active(const struct dm_crtc_state *dm_state);
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_crtc_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_crtc_test.c
index 430765dd87a3..7abd85be3019 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_crtc_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_crtc_test.c
@@ -10,6 +10,7 @@
 #include <drm/drm_connector.h>
 #include <drm/drm_kunit_helpers.h>
 #include <drm/drm_vblank.h>
+#include <linux/debugfs.h>
 
 #include "dc.h"
 #include "inc/core_types.h"
@@ -1990,6 +1991,33 @@ static void dm_test_crtc_disable_vblank_queues_work(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, adev->dm.active_vblank_irq_count, 1);
 }
 
+#ifdef CONFIG_DEBUG_FS
+/**
+ * dm_test_crtc_late_register_inits_debugfs - Test late_register succeeds
+ * @test: The KUnit test context
+ *
+ * amdgpu_dm_crtc_late_register populates the CRTC's debugfs entries via
+ * crtc_debugfs_init and must return 0. Provide a debugfs parent so the
+ * helper attaches its files there, then tear it down.
+ */
+static void dm_test_crtc_late_register_inits_debugfs(struct kunit *test)
+{
+	struct drm_crtc *crtc;
+	int ret;
+
+	crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc);
+
+	crtc->debugfs_entry = debugfs_create_dir("dm_test_crtc", NULL);
+
+	ret = amdgpu_dm_crtc_late_register(crtc);
+
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	debugfs_remove_recursive(crtc->debugfs_entry);
+}
+#endif
+
 static struct kunit_case amdgpu_dm_crtc_tests[] = {
 	/* amdgpu_dm_crtc_modeset_required */
 	KUNIT_CASE(dm_test_crtc_modeset_required_active_mode_changed),
@@ -2071,6 +2099,10 @@ static struct kunit_case amdgpu_dm_crtc_tests[] = {
 	KUNIT_CASE(dm_test_crtc_disable_vblank_no_irq_installed),
 	KUNIT_CASE(dm_test_crtc_disable_vblank_vrr),
 	KUNIT_CASE(dm_test_crtc_disable_vblank_queues_work),
+#ifdef CONFIG_DEBUG_FS
+	/* amdgpu_dm_crtc_late_register */
+	KUNIT_CASE(dm_test_crtc_late_register_inits_debugfs),
+#endif
 	{}
 };
 
-- 
2.43.0