}
 EXPORT_SYMBOL(drm_atomic_get_crtc_state);
 
+/**
+ * drm_atomic_set_mode_for_crtc - set mode for CRTC
+ * @state: the CRTC whose incoming state to update
+ * @mode: kernel-internal mode to use for the CRTC, or NULL to disable
+ *
+ * Set a mode (originating from the kernel) on the desired CRTC state. Does
+ * not change any other state properties, including enable, active, or
+ * mode_changed.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure. Cannot return -EDEADLK.
+ */
+int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
+                                struct drm_display_mode *mode)
+{
+       /* Early return for no change. */
+       if (mode && memcmp(&state->mode, mode, sizeof(*mode)) == 0)
+               return 0;
+
+       if (mode) {
+               drm_mode_copy(&state->mode, mode);
+               state->enable = true;
+               DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
+                                mode->name, state);
+       } else {
+               memset(&state->mode, 0, sizeof(state->mode));
+               state->enable = false;
+               DRM_DEBUG_ATOMIC("Set [NOMODE] for CRTC state %p\n",
+                                state);
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_atomic_set_mode_for_crtc);
+
+
 /**
  * drm_atomic_crtc_set_property - set property on CRTC
  * @crtc: the drm CRTC to set a property on
 
                WARN_ON(set->fb);
                WARN_ON(set->num_connectors);
 
-               crtc_state->enable = false;
+               ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
+               if (ret != 0)
+                       goto fail;
+
                crtc_state->active = false;
 
                ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
        WARN_ON(!set->fb);
        WARN_ON(!set->num_connectors);
 
-       crtc_state->enable = true;
+       ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
+       if (ret != 0)
+               goto fail;
+
        crtc_state->active = true;
-       drm_mode_copy(&crtc_state->mode, set->mode);
 
        ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
        if (ret != 0)
 
                        crtc_state->crtc = crtc;
        }
 
-       crtc_state->enable = true;
        crtc_state->planes_changed = true;
        crtc_state->mode_changed = true;
-       drm_mode_copy(&crtc_state->mode, mode);
+       ret = drm_atomic_set_mode_for_crtc(crtc_state, mode);
+       if (ret)
+               goto out;
        drm_mode_copy(&crtc_state->adjusted_mode, adjusted_mode);
 
        if (crtc_funcs->atomic_check) {
 
        return state->connector_states[index];
 }
 
+int __must_check
+drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
+                            struct drm_display_mode *mode);
 int __must_check
 drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
                              struct drm_crtc *crtc);