Fix output enable in DRM backend

backend/drm/atomic.c

@@ -123,14 +123,22 @@ static bool atomic_crtc_pageflip(struct wlr_drm_backend *drm,
 		mode);
 }
 
-static void atomic_conn_enable(struct wlr_drm_backend *drm,
+static bool atomic_conn_enable(struct wlr_drm_backend *drm,
 		struct wlr_drm_connector *conn, bool enable) {
 	struct wlr_drm_crtc *crtc = conn->crtc;
-	struct atomic atom;
 
+	struct atomic atom;
 	atomic_begin(crtc, &atom);
 	atomic_add(&atom, crtc->id, crtc->props.active, enable);
-	atomic_end(drm->fd, &atom);
+	if (enable) {
+		atomic_add(&atom, conn->id, conn->props.crtc_id, crtc->id);
+		atomic_add(&atom, crtc->id, crtc->props.mode_id, crtc->mode_id);
+	} else {
+		atomic_add(&atom, conn->id, conn->props.crtc_id, 0);
+		atomic_add(&atom, crtc->id, crtc->props.mode_id, 0);
+	}
+	return atomic_commit(drm->fd, &atom, conn, DRM_MODE_ATOMIC_ALLOW_MODESET,
+		true);
 }
 
 bool legacy_crtc_set_cursor(struct wlr_drm_backend *drm,

backend/drm/drm.c

@@ -252,7 +252,10 @@ static void wlr_drm_connector_enable(struct wlr_output *output, bool enable) {
 	}
 
 	struct wlr_drm_backend *drm = (struct wlr_drm_backend *)output->backend;
-	drm->iface->conn_enable(drm, conn, enable);
+	bool ok = drm->iface->conn_enable(drm, conn, enable);
+	if (!ok) {
+		return;
+	}
 
 	if (enable) {
 		wlr_drm_connector_start_renderer(conn);

backend/drm/legacy.c

@@ -25,10 +25,11 @@ static bool legacy_crtc_pageflip(struct wlr_drm_backend *drm,
 	return true;
 }
 
-static void legacy_conn_enable(struct wlr_drm_backend *drm,
+static bool legacy_conn_enable(struct wlr_drm_backend *drm,
 		struct wlr_drm_connector *conn, bool enable) {
-	drmModeConnectorSetProperty(drm->fd, conn->id, conn->props.dpms,
+	int ret = drmModeConnectorSetProperty(drm->fd, conn->id, conn->props.dpms,
 		enable ? DRM_MODE_DPMS_ON : DRM_MODE_DPMS_OFF);
+	return ret >= 0;
 }
 
 bool legacy_crtc_set_cursor(struct wlr_drm_backend *drm,

include/backend/drm/iface.h

@@ -15,7 +15,7 @@ struct wlr_drm_crtc;
 // Used to provide atomic or legacy DRM functions
 struct wlr_drm_interface {
 	// Enable or disable DPMS for connector
-	void (*conn_enable)(struct wlr_drm_backend *drm,
+	bool (*conn_enable)(struct wlr_drm_backend *drm,
 		struct wlr_drm_connector *conn, bool enable);
 	// Pageflip on crtc. If mode is non-NULL perform a full modeset using it.
 	bool (*crtc_pageflip)(struct wlr_drm_backend *drm,