4 files changed, 30 insertions, 31 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index e49b22381048..1cc3a045ec2f 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -308,6 +308,26 @@ update_connector_routing(struct drm_atomic_state *state,
 		return 0;
 	}
 
+	crtc_state = drm_atomic_get_new_crtc_state(state,
+						   new_connector_state->crtc);
+	/*
+	 * For compatibility with legacy users, we want to make sure that
+	 * we allow DPMS On->Off modesets on unregistered connectors. Modesets
+	 * which would result in anything else must be considered invalid, to
+	 * avoid turning on new displays on dead connectors.
+	 *
+	 * Since the connector can be unregistered at any point during an
+	 * atomic check or commit, this is racy. But that's OK: all we care
+	 * about is ensuring that userspace can't do anything but shut off the
+	 * display on a connector that was destroyed after its been notified,
+	 * not before.
+	 */
+	if (drm_connector_is_unregistered(connector) && crtc_state->active) {
+		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
+				 connector->base.id, connector->name);
+		return -EINVAL;
+	}
+
 	funcs = connector->helper_private;
 
 	if (funcs->atomic_best_encoder)
@@ -352,7 +372,6 @@ update_connector_routing(struct drm_atomic_state *state,
 
 	set_best_encoder(state, new_connector_state, new_encoder);
 
-	crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state->crtc);
 	crtc_state->connectors_changed = true;
 
 	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index a22d6f269b07..d5b7f315098c 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -299,27 +299,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 	struct drm_connector *connector = conn_state->connector;
 	struct drm_crtc_state *crtc_state;
 
-	/*
-	 * For compatibility with legacy users, we want to make sure that
-	 * we allow DPMS On<->Off modesets on unregistered connectors, since
-	 * legacy modesetting users will not be expecting these to fail. We do
-	 * not however, want to allow legacy users to assign a connector
-	 * that's been unregistered from sysfs to another CRTC, since doing
-	 * this with a now non-existent connector could potentially leave us
-	 * in an invalid state.
-	 *
-	 * Since the connector can be unregistered at any point during an
-	 * atomic check or commit, this is racy. But that's OK: all we care
-	 * about is ensuring that userspace can't use this connector for new
-	 * configurations after it's been notified that the connector is no
-	 * longer present.
-	 */
-	if (!READ_ONCE(connector->registered) && crtc) {
-		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
-				 connector->base.id, connector->name);
-		return -EINVAL;
-	}
-
 	if (conn_state->crtc == crtc)
 		return 0;
 
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 1e40e5decbe9..4943cef178be 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -379,7 +379,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	/* The connector should have been removed from userspace long before
 	 * it is finally destroyed.
 	 */
-	if (WARN_ON(connector->registered))
+	if (WARN_ON(connector->registration_state ==
+		    DRM_CONNECTOR_REGISTERED))
 		drm_connector_unregister(connector);
 
 	if (connector->tile_group) {
@@ -436,7 +437,7 @@ int drm_connector_register(struct drm_connector *connector)
 		return 0;
 
 	mutex_lock(&connector->mutex);
-	if (connector->registered)
+	if (connector->registration_state != DRM_CONNECTOR_INITIALIZING)
 		goto unlock;
 
 	ret = drm_sysfs_connector_add(connector);
@@ -456,7 +457,7 @@ int drm_connector_register(struct drm_connector *connector)
 
 	drm_mode_object_register(connector->dev, &connector->base);
 
-	connector->registered = true;
+	connector->registration_state = DRM_CONNECTOR_REGISTERED;
 	goto unlock;
 
 err_debugfs:
@@ -478,7 +479,7 @@ EXPORT_SYMBOL(drm_connector_register);
 void drm_connector_unregister(struct drm_connector *connector)
 {
 	mutex_lock(&connector->mutex);
-	if (!connector->registered) {
+	if (connector->registration_state != DRM_CONNECTOR_REGISTERED) {
 		mutex_unlock(&connector->mutex);
 		return;
 	}
@@ -489,7 +490,7 @@ void drm_connector_unregister(struct drm_connector *connector)
 	drm_sysfs_connector_remove(connector);
 	drm_debugfs_connector_remove(connector);
 
-	connector->registered = false;
+	connector->registration_state = DRM_CONNECTOR_UNREGISTERED;
 	mutex_unlock(&connector->mutex);
 }
 EXPORT_SYMBOL(drm_connector_unregister);
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 7f155b4f1a7d..1b00f8ea145b 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -77,7 +77,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	pipe_config->pbn = mst_pbn;
 
 	/* Zombie connectors can't have VCPI slots */
-	if (READ_ONCE(connector->registered)) {
+	if (!drm_connector_is_unregistered(connector)) {
 		slots = drm_dp_atomic_find_vcpi_slots(state,
 						      &intel_dp->mst_mgr,
 						      port,
@@ -313,7 +313,7 @@ static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
 	struct edid *edid;
 	int ret;
 
-	if (!READ_ONCE(connector->registered))
+	if (drm_connector_is_unregistered(connector))
 		return intel_connector_update_modes(connector, NULL);
 
 	edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
@@ -329,7 +329,7 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct intel_dp *intel_dp = intel_connector->mst_port;
 
-	if (!READ_ONCE(connector->registered))
+	if (drm_connector_is_unregistered(connector))
 		return connector_status_disconnected;
 	return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr,
 				      intel_connector->port);
@@ -372,7 +372,7 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
 	int bpp = 24; /* MST uses fixed bpp */
 	int max_rate, mode_rate, max_lanes, max_link_clock;
 
-	if (!READ_ONCE(connector->registered))
+	if (drm_connector_is_unregistered(connector))
 		return MODE_ERROR;
 
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)