Don't allocate a framebuffer if no interface ports have been configured.

ok patrick@

sys/dev/fdt/rkdrm.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: rkdrm.c,v 1.3 2020/03/16 21:51:25 kettenis Exp $ */
+/* $OpenBSD: rkdrm.c,v 1.4 2020/03/22 14:56:24 kettenis Exp $ */
 /* $NetBSD: rk_drm.c,v 1.3 2019/12/15 01:00:58 mrg Exp $ */
 /*-
  * Copyright (c) 2019 Jared D. McNeill <jmcneill@invisible.ca>
@@ -422,6 +422,7 @@ rkdrm_attachhook(struct device *dev)
 	struct drm_device *ddev;
 	uint32_t *ports;
 	int i, portslen, nports;
+	int error;
 
 	portslen = OF_getproplen(sc->sc_node, "ports");
 	if (portslen < 0) {
@@ -441,8 +442,9 @@ rkdrm_attachhook(struct device *dev)
 	ports = malloc(portslen, M_TEMP, M_WAITOK);
 	OF_getpropintarray(sc->sc_node, "ports", ports, portslen);
 	for (i = 0; i < portslen / sizeof(uint32_t); i++) {
-		device_port_activate(ports[i], &sc->sc_ddev);
-		nports++;
+		error = device_port_activate(ports[i], &sc->sc_ddev);
+		if (error == 0)
+			nports++;
 	}
 	free(ports, M_TEMP, portslen);
 

sys/dev/ofw/ofw_misc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.c,v 1.17 2020/03/21 22:45:18 patrick Exp $	*/
+/*	$OpenBSD: ofw_misc.c,v 1.18 2020/03/22 14:56:24 kettenis Exp $	*/
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -565,11 +565,12 @@ endpoint_get_cookie(struct endpoint *ep)
 	return ports->dp_ep_get_cookie(ports->dp_cookie, ep);
 }
 
-void
+int
 device_port_activate(uint32_t phandle, void *arg)
 {
 	struct device_port *dp = NULL;
 	struct endpoint *ep, *rep;
+	int count;
 	int error;
 
 	LIST_FOREACH(ep, &endpoints, ep_list) {
@@ -579,8 +580,9 @@ device_port_activate(uint32_t phandle, void *arg)
 		}
 	}
 	if (dp == NULL)
-		return;
+		return ENXIO;
 
+	count = 0;
 	LIST_FOREACH(ep, &dp->dp_endpoints, ep_plist) {
 		rep = endpoint_remote(ep);
 		if (rep == NULL)
@@ -592,5 +594,8 @@ device_port_activate(uint32_t phandle, void *arg)
 		error = endpoint_activate(rep, arg);
 		if (error)
 			continue;
+		count++;
 	}
+
+	return count ? 0 : ENXIO;
 }

sys/dev/ofw/ofw_misc.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.h,v 1.11 2020/03/16 21:51:26 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.h,v 1.12 2020/03/22 14:56:24 kettenis Exp $	*/
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -171,7 +171,7 @@ struct endpoint {
 };
 
 void	device_ports_register(struct device_ports *, enum endpoint_type);
-void	device_port_activate(uint32_t, void *);
+int	device_port_activate(uint32_t, void *);
 struct endpoint *endpoint_byreg(struct device_ports *, uint32_t, uint32_t);
 struct endpoint *endpoint_remote(struct endpoint *);
 int	endpoint_activate(struct endpoint *, void *);