drm/amdgpu: dm: Convert to atomic_create_state

The amdgpu display manager crtc implementation provides a custom reset
hook. However, this hook only allocates the state, initializes it with
__drm_atomic_helper_crtc_reset(), and frees the previous state. It
does not perform any hardware reset.

Since this is exactly what the atomic_create_state hook is meant to
do, minus the old state cleanup which the caller handles, convert the
implementation to use atomic_create_state with
__drm_atomic_helper_crtc_state_init() instead.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20260904-drm-no-more-crtc-reset-v3-7-27d9891512ce@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>

3 files changed, 33 insertions, 23 deletions

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 62eac6e65334..53910056da20 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
@@ -475,20 +475,19 @@ static void amdgpu_dm_crtc_destroy(struct drm_crtc *crtc)
 	kfree(crtc);
 }
 
-STATIC_IFN_KUNIT void amdgpu_dm_crtc_reset_state(struct drm_crtc *crtc)
+STATIC_IFN_KUNIT struct drm_crtc_state *amdgpu_dm_crtc_create_state(struct drm_crtc *crtc)
 {
 	struct dm_crtc_state *state;
 
 	state = kzalloc_obj(*state);
 	if (!state)
-		return;
+		return ERR_PTR(-ENOMEM);
 
-	if (crtc->state)
-		amdgpu_dm_crtc_destroy_state(crtc, crtc->state);
+	__drm_atomic_helper_crtc_state_init(&state->base, crtc);
 
-	__drm_atomic_helper_crtc_reset(crtc, &state->base);
+	return &state->base;
 }
-EXPORT_IF_KUNIT(amdgpu_dm_crtc_reset_state);
+EXPORT_IF_KUNIT(amdgpu_dm_crtc_create_state);
 
 #ifdef CONFIG_DEBUG_FS
 static int amdgpu_dm_crtc_late_register(struct drm_crtc *crtc)
@@ -565,7 +564,7 @@ amdgpu_dm_atomic_crtc_get_property(struct drm_crtc *crtc,
 
 /* Implemented only the options currently available for the driver */
 static const struct drm_crtc_funcs amdgpu_dm_crtc_funcs = {
-	.reset = amdgpu_dm_crtc_reset_state,
+	.atomic_create_state = amdgpu_dm_crtc_create_state,
 	.destroy = amdgpu_dm_crtc_destroy,
 	.set_config = drm_atomic_helper_set_config,
 	.page_flip = drm_atomic_helper_page_flip,
@@ -781,9 +780,18 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm,
 
 	drm_crtc_helper_add(&acrtc->base, &amdgpu_dm_crtc_helper_funcs);
 
-	/* Create (reset) the plane state */
-	if (acrtc->base.funcs->reset)
-		acrtc->base.funcs->reset(&acrtc->base);
+	/* Create the plane state */
+	if (acrtc->base.funcs->atomic_create_state) {
+		struct drm_crtc_state *crtc_state;
+
+		crtc_state = acrtc->base.funcs->atomic_create_state(&acrtc->base);
+		if (IS_ERR(crtc_state)) {
+			res = PTR_ERR(crtc_state);
+			goto error_ism_fini;
+		}
+
+		acrtc->base.state = crtc_state;
+	}
 
 	acrtc->max_cursor_width = dm->adev->dm.dc->caps.max_cursor_size;
 	acrtc->max_cursor_height = dm->adev->dm.dc->caps.max_cursor_size;
@@ -815,6 +823,9 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm,
 #endif
 	return 0;
 
+error_ism_fini:
+	amdgpu_dm_ism_fini(&acrtc->ism);
+	drm_crtc_cleanup(&acrtc->base);
 fail:
 	kfree(acrtc);
 	kfree(cursor_plane);
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 93c6d0d8d7fd..ad516aeb9798 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
@@ -49,7 +49,7 @@ bool amdgpu_dm_crtc_helper_mode_fixup(struct drm_crtc *crtc,
 void amdgpu_dm_crtc_destroy_state(struct drm_crtc *crtc,
 				  struct drm_crtc_state *state);
 struct drm_crtc_state *amdgpu_dm_crtc_duplicate_state(struct drm_crtc *crtc);
-void amdgpu_dm_crtc_reset_state(struct drm_crtc *crtc);
+struct drm_crtc_state *amdgpu_dm_crtc_create_state(struct drm_crtc *crtc);
 int amdgpu_dm_crtc_count_crtc_active_planes(struct drm_crtc_state *new_crtc_state);
 void amdgpu_dm_crtc_update_crtc_active_planes(struct drm_crtc *crtc,
 					      struct drm_crtc_state *new_crtc_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 0d998f204250..17bd64611a82 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
@@ -1404,18 +1404,18 @@ static void dm_test_crtc_duplicate_state_copies_fields(struct kunit *test)
 	amdgpu_dm_crtc_destroy_state(crtc, dup);
 }
 
-/* Tests for amdgpu_dm_crtc_reset_state() */
+/* Tests for amdgpu_dm_crtc_create_state() */
 
 /**
- * dm_test_crtc_reset_state_allocates_state - Test reset installs a fresh state
+ * dm_test_crtc_create_state_allocates_state - Test create_state allocates a fresh state
  * @test: The KUnit test context
  *
- * Resetting a CRTC with no existing state must allocate and install a new
- * drm_crtc_state.
+ * Creating state for a CRTC must allocate a new drm_crtc_state.
  */
-static void dm_test_crtc_reset_state_allocates_state(struct kunit *test)
+static void dm_test_crtc_create_state_allocates_state(struct kunit *test)
 {
 	struct amdgpu_device *adev = dm_kunit_alloc_adev(test);
+	struct drm_crtc_state *crtc_state;
 	struct drm_crtc *crtc;
 
 	crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL);
@@ -1423,12 +1423,11 @@ static void dm_test_crtc_reset_state_allocates_state(struct kunit *test)
 	crtc->dev = &adev->ddev;
 	crtc->state = NULL;
 
-	amdgpu_dm_crtc_reset_state(crtc);
-
-	KUNIT_EXPECT_NOT_NULL(test, crtc->state);
+	crtc_state = amdgpu_dm_crtc_create_state(crtc);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, crtc_state);
 
-	if (crtc->state)
-		amdgpu_dm_crtc_destroy_state(crtc, crtc->state);
+	if (!IS_ERR(crtc_state))
+		amdgpu_dm_crtc_destroy_state(crtc, crtc_state);
 }
 
 /* Tests for amdgpu_dm_crtc_destroy_state() */
@@ -1907,8 +1906,8 @@ static struct kunit_case amdgpu_dm_crtc_tests[] = {
 	KUNIT_CASE(dm_test_count_crtc_active_planes_mixed),
 	/* amdgpu_dm_crtc_duplicate_state */
 	KUNIT_CASE(dm_test_crtc_duplicate_state_copies_fields),
-	/* amdgpu_dm_crtc_reset_state */
-	KUNIT_CASE(dm_test_crtc_reset_state_allocates_state),
+	/* amdgpu_dm_crtc_create_state */
+	KUNIT_CASE(dm_test_crtc_create_state_allocates_state),
 	/* amdgpu_dm_crtc_destroy_state */
 	KUNIT_CASE(dm_test_crtc_destroy_state_no_stream),
 	KUNIT_CASE(dm_test_crtc_destroy_state_releases_stream),