drm/atomic: use connector references (v3)

Take a reference when setting a crtc on a connecter,
also take one when duplicating if a crtc is set,
and drop one on destroy if a crtc is set.

v2: take Daniel Stone's advice and simplify the
ref/unref dances, also take care of NULL as connector
to state reset.

v3: remove need for connector NULL check.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 9 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index e4879d34c280..86e89db02ed7 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -144,15 +144,7 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
                 if (!connector)
                         continue;
 
-                /*
-                 * FIXME: Nonblocking commits can race with connector unplugging and
-                 * there's currently nothing that prevents cleanup up state for
-                 * deleted connectors. As long as the callback doesn't look at
-                 * the connector we'll be fine though, so make sure that's the
-                 * case by setting all connector pointers to NULL.
-                 */
-                state->connector_states[i]->connector = NULL;
-                connector->funcs->atomic_destroy_state(NULL,
+                connector->funcs->atomic_destroy_state(connector,
                                                        state->connector_states[i]);
                 state->connectors[i] = NULL;
                 state->connector_states[i] = NULL;
@@ -1168,6 +1160,8 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 {
         struct drm_crtc_state *crtc_state;
 
+        if (crtc)
+                drm_connector_reference(conn_state->connector);
         if (conn_state->crtc && conn_state->crtc != crtc) {
                 crtc_state = drm_atomic_get_existing_crtc_state(conn_state->state,
                                                                 conn_state->crtc);
@@ -1185,6 +1179,8 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
                         1 << drm_connector_index(conn_state->connector);
         }
 
+        if (conn_state->crtc)
+                drm_connector_unreference(conn_state->connector);
         conn_state->crtc = crtc;
 
         if (crtc)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 92e11a2b83c8..997fd21e5388 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2762,6 +2762,8 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
                                             struct drm_connector_state *state)
 {
         memcpy(state, connector->state, sizeof(*state));
+        if (state->crtc)
+                drm_connector_reference(connector);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 
@@ -2889,6 +2891,8 @@ __drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
          * state will automatically do the right thing if code is ever added
          * to this function.
          */
+        if (state->crtc)
+                drm_connector_unreference(state->connector);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);