2 files changed, 18 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 440cfa91162a..c53ecbd9abdd 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -332,8 +332,15 @@ update_connector_routing(struct drm_atomic_state *state,
          * about is ensuring that userspace can't do anything but shut off the
          * display on a connector that was destroyed after it's been notified,
          * not before.
+         *
+         * Additionally, we also want to ignore connector registration when
+         * we're trying to restore an atomic state during system resume since
+         * there's a chance the connector may have been destroyed during the
+         * process, but it's better to ignore that then cause
+         * drm_atomic_helper_resume() to fail.
          */
-        if (drm_connector_is_unregistered(connector) && crtc_state->active) {
+        if (!state->duplicated && 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;
@@ -3180,6 +3187,7 @@ drm_atomic_helper_duplicate_state(struct drm_device *dev,
                 return ERR_PTR(-ENOMEM);
 
         state->acquire_ctx = ctx;
+        state->duplicated = true;
 
         drm_for_each_crtc(crtc, dev) {
                 struct drm_crtc_state *crtc_state;
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index dc7ac0c60547..5a99135d39cd 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3097,6 +3097,10 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
  * @port as needed. It is not OK however, to call this function and
  * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
  *
+ * When &drm_atomic_state.duplicated is set to %true%, this function will not
+ * perform any error checking and will instead simply return the previously
+ * recorded VCPI allocations.
+ *
  * See also:
  * drm_dp_atomic_release_vcpi_slots()
  * drm_dp_mst_atomic_check()
@@ -3181,6 +3185,11 @@ EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
  * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
  * phase.
  *
+ * When &drm_atomic_state.duplicated is set, this function will not
+ * modify the VCPI allocations in &drm_dp_mst_topology_state.vcpis, so that
+ * those VCPI allocations may be restored as-is from the duplicated state. In
+ * this scenario, this function will always return 0.
+ *
  * See also:
  * drm_dp_atomic_find_vcpi_slots()
  * drm_dp_mst_atomic_check()