drm backend: detect non-desktop outputs

backend/drm/drm.c

@@ -1206,8 +1206,8 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 				drm->display);
 
 			struct wl_event_loop *ev = wl_display_get_event_loop(drm->display);
-			wlr_conn->retry_pageflip = wl_event_loop_add_timer(ev, retry_pageflip,
+			wlr_conn->retry_pageflip = wl_event_loop_add_timer(
-				wlr_conn);
+					ev, retry_pageflip, wlr_conn);
 
 			wlr_conn->state = WLR_DRM_CONN_DISCONNECTED;
 			wlr_conn->id = drm_conn->connector_id;
@@ -1269,6 +1269,12 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 
 			get_drm_connector_props(drm->fd, wlr_conn->id, &wlr_conn->props);
 
+			uint64_t non_desktop;
+			if (get_drm_prop(drm->fd, wlr_conn->id,
+						wlr_conn->props.non_desktop, &non_desktop)) {
+				wlr_conn->output.non_desktop = non_desktop;
+			}
+
 			size_t edid_len = 0;
 			uint8_t *edid = get_drm_prop_blob(drm->fd,
 				wlr_conn->id, wlr_conn->props.edid, &edid_len);

backend/drm/properties.c

@@ -24,6 +24,7 @@ static const struct prop_info connector_info[] = {
 	{ "EDID", INDEX(edid) },
 	{ "PATH", INDEX(path) },
 	{ "link-status", INDEX(link_status) },
+	{ "non-desktop", INDEX(non_desktop) },
 #undef INDEX
 };
 

include/backend/drm/properties.h

@@ -16,6 +16,7 @@ union wlr_drm_connector_props {
 		uint32_t dpms;
 		uint32_t link_status; // not guaranteed to exist
 		uint32_t path;
+		uint32_t non_desktop;
 
 		// atomic-modesetting only
 

include/wlr/types/wlr_output.h

@@ -112,6 +112,9 @@ struct wlr_output {
 	bool frame_pending;
 	float transform_matrix[9];
 
+	// true, for example, with VR headsets
+	bool non_desktop;
+
 	struct wlr_output_state pending;
 
 	struct {