--- a/sys/dev/drm/drm_atomic_helper.c
+++ b/sys/dev/drm/drm_atomic_helper.c
@@ -459,7 +459,7 @@ mode_fixup(struct drm_atomic_state *state)
 		if (!new_crtc_state->enable)
 			continue;
 
 		if (!new_crtc_state->mode_changed &&
 		    !new_crtc_state->connectors_changed)
 			continue;
 
 		funcs = crtc->helper_private;
-		if (!funcs->mode_fixup)
+		if (!funcs || !funcs->mode_fixup)
 			continue;
 
 		ret = funcs->mode_fixup(crtc, &new_crtc_state->mode,
 					&new_crtc_state->adjusted_mode);
@@ -1003,10 +1003,11 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
 
 		/* Right function depends upon target state. */
 		if (new_crtc_state->enable && funcs->prepare)
 			funcs->prepare(crtc);
 		else if (funcs->atomic_disable)
 			funcs->atomic_disable(crtc, old_crtc_state);
 		else if (funcs->disable)
 			funcs->disable(crtc);
-		else
+		else if (funcs->dpms)
 			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
 
 		if (!(dev->irq_enabled && dev->num_crtcs))
 			continue;
@@ -1253,8 +1254,9 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
 		if (new_crtc_state->enable) {
 			DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
 					 crtc->base.id, crtc->name);
 			if (funcs->atomic_enable)
 				funcs->atomic_enable(crtc, old_crtc_state);
-			else
+			else if (funcs->commit)
 				funcs->commit(crtc);
 		}
 	}