diff --git a/sys/dev/wscons/wsdisplay.c b/sys/dev/wscons/wsdisplay.c
index 8006e980dc36..66dc8dc5ef6e 100644
--- a/sys/dev/wscons/wsdisplay.c
+++ b/sys/dev/wscons/wsdisplay.c
@@ -1,4 +1,4 @@
-/* $NetBSD: wsdisplay.c,v 1.32 1999/12/01 23:22:59 augustss Exp $ */
+/* $NetBSD: wsdisplay.c,v 1.33 1999/12/06 18:52:23 drochner Exp $ */
 
 /*
  * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
@@ -33,7 +33,7 @@
 static const char _copyright[] __attribute__ ((unused)) =
     "Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.";
 static const char _rcsid[] __attribute__ ((unused)) =
-    "$NetBSD: wsdisplay.c,v 1.32 1999/12/01 23:22:59 augustss Exp $";
+    "$NetBSD: wsdisplay.c,v 1.33 1999/12/06 18:52:23 drochner Exp $";
 
 #include <sys/param.h>
 #include <sys/conf.h>
@@ -199,11 +199,14 @@ static struct wsdisplay_softc *wsdisplay_console_device;
 static struct wsscreen_internal wsdisplay_console_conf;
 
 static int wsdisplay_getc_dummy __P((dev_t));
-static void wsdisplay_pollc_dummy __P((dev_t, int));
+static void wsdisplay_pollc __P((dev_t, int));
+
+static int wsdisplay_cons_pollmode;
+static void (*wsdisplay_cons_kbd_pollc) __P((dev_t, int));
 
 static struct consdev wsdisplay_cons = {
 	NULL, NULL, wsdisplay_getc_dummy, wsdisplay_cnputc,
-	wsdisplay_pollc_dummy, NODEV, CN_NORMAL
+	wsdisplay_pollc, NODEV, CN_NORMAL
 };
 
 #ifndef WSDISPLAY_DEFAULTSCREENS
@@ -212,6 +215,7 @@ static struct consdev wsdisplay_cons = {
 int wsdisplay_defaultscreens = WSDISPLAY_DEFAULTSCREENS;
 
 int wsdisplay_switch1 __P((void *, int, int));
+int wsdisplay_switch2 __P((void *, int, int));
 int wsdisplay_switch3 __P((void *, int, int));
 
 int wsdisplay_clearonclose;
@@ -378,7 +382,8 @@ wsdisplay_addscreen(sc, idx, screentype, emul)
 	s = spltty();
 	if (!sc->sc_focus) {
 		(*sc->sc_accessops->show_screen)(sc->sc_accesscookie,
-						 scr->scr_dconf->emulcookie);
+						 scr->scr_dconf->emulcookie,
+						 0, 0, 0);
 		sc->sc_focusidx = idx;
 		sc->sc_focus = scr;
 	}
@@ -1405,6 +1410,65 @@ wsdisplay_switch3(arg, error, waitok)
 	return (error);
 }
 
+int
+wsdisplay_switch2(arg, error, waitok)
+	void *arg;
+	int error, waitok;
+{
+	struct wsdisplay_softc *sc = arg;
+	int no;
+	struct wsscreen *scr;
+
+	if (!(sc->sc_flags & SC_SWITCHPENDING)) {
+		printf("wsdisplay_switch2: not switching\n");
+		return (EINVAL);
+	}
+
+	no = sc->sc_screenwanted;
+	if (no < 0 || no >= WSDISPLAY_MAXSCREEN)
+		panic("wsdisplay_switch2: invalid screen %d", no);
+	scr = sc->sc_scr[no];
+	if (!scr) {
+		printf("wsdisplay_switch2: screen %d disappeared\n", no);
+		error = ENXIO;
+	}
+
+	if (error) {
+		/* try to recover, avoid recursion */
+
+		if (sc->sc_oldscreen == -1) {
+			printf("wsdisplay_switch2: giving up\n");
+			sc->sc_focus = 0;
+			sc->sc_flags &= ~SC_SWITCHPENDING;
+			return (error);
+		}
+
+		sc->sc_screenwanted = sc->sc_oldscreen;
+		sc->sc_oldscreen = -1;
+		return (wsdisplay_switch1(arg, 0, waitok));
+	}
+
+	sc->sc_focusidx = no;
+	sc->sc_focus = scr;
+
+#ifdef WSDISPLAY_COMPAT_RAWKBD
+	(void) wsdisplay_update_rawkbd(sc, scr);
+#endif
+	/* keyboard map??? */
+
+#define wsswitch_cb3 ((void (*) __P((void *, int, int)))wsdisplay_switch3)
+	if (scr->scr_syncops) {
+		error = (*scr->scr_syncops->attach)(scr->scr_synccookie, waitok,
+	  sc->sc_isconsole && wsdisplay_cons_pollmode ? 0 : wsswitch_cb3, sc);
+		if (error == EAGAIN) {
+			/* switch will be done asynchronously */
+			return (0);
+		}
+	}
+
+	return (wsdisplay_switch3(sc, error, waitok));
+}
+
 int
 wsdisplay_switch1(arg, error, waitok)
 	void *arg;
@@ -1433,27 +1497,17 @@ wsdisplay_switch1(arg, error, waitok)
 		return (error);
 	}
 
-	(*sc->sc_accessops->show_screen)(sc->sc_accesscookie,
-					 scr->scr_dconf->emulcookie);
-	sc->sc_focusidx = no;
-	sc->sc_focus = scr;
-
-#ifdef WSDISPLAY_COMPAT_RAWKBD
-	(void) wsdisplay_update_rawkbd(sc, scr);
-#endif
-	/* keyboard map??? */
-
-#define wsswitch_cb3 ((void (*) __P((void *, int, int)))wsdisplay_switch3)
-	if (scr->scr_syncops) {
-		error = (*scr->scr_syncops->attach)(scr->scr_synccookie, waitok,
-						    wsswitch_cb3, sc);
-		if (error == EAGAIN) {
-			/* switch will be done asynchronously */
-			return (0);
-		}
+#define wsswitch_cb2 ((void (*) __P((void *, int, int)))wsdisplay_switch2)
+	error = (*sc->sc_accessops->show_screen)(sc->sc_accesscookie,
+						 scr->scr_dconf->emulcookie,
+						 waitok,
+	  sc->sc_isconsole && wsdisplay_cons_pollmode ? 0 : wsswitch_cb2, sc);
+	if (error == EAGAIN) {
+		/* switch will be done asynchronously */
+		return (0);
 	}
 
-	return (wsdisplay_switch3(sc, error, waitok));
+	return (wsdisplay_switch2(sc, error, waitok));
 }
 
 int
@@ -1495,7 +1549,7 @@ wsdisplay_switch(dev, no, waitok)
 #define wsswitch_cb1 ((void (*) __P((void *, int, int)))wsdisplay_switch1)
 	if (scr->scr_syncops) {
 		res = (*scr->scr_syncops->detach)(scr->scr_synccookie, waitok,
-						  wsswitch_cb1, sc);
+	  sc->sc_isconsole && wsdisplay_cons_pollmode ? 0 : wsswitch_cb1, sc);
 		if (res == EAGAIN) {
 			/* switch will be done asynchronously */
 			return (0);
@@ -1697,10 +1751,15 @@ wsdisplay_getc_dummy(dev)
 }
 
 static void
-wsdisplay_pollc_dummy(dev, on)
+wsdisplay_pollc(dev, on)
 	dev_t dev;
 	int on;
 {
+
+	wsdisplay_cons_pollmode = on;
+
+	if (wsdisplay_cons_kbd_pollc)
+		(*wsdisplay_cons_kbd_pollc)(dev, on);
 }
 
 void
@@ -1709,14 +1768,14 @@ wsdisplay_set_cons_kbd(get, poll)
 	void (*poll) __P((dev_t, int));
 {
 	wsdisplay_cons.cn_getc = get;
-	wsdisplay_cons.cn_pollc = poll;
+	wsdisplay_cons_kbd_pollc = poll;
 }
 
 void
 wsdisplay_unset_cons_kbd()
 {
 	wsdisplay_cons.cn_getc = wsdisplay_getc_dummy;
-	wsdisplay_cons.cn_pollc = wsdisplay_pollc_dummy;
+	wsdisplay_cons_kbd_pollc = 0;
 }
 
 /*
diff --git a/sys/dev/wscons/wsdisplay_compat_usl.c b/sys/dev/wscons/wsdisplay_compat_usl.c
index 1ac3758e2203..ed7814e4dffb 100644
--- a/sys/dev/wscons/wsdisplay_compat_usl.c
+++ b/sys/dev/wscons/wsdisplay_compat_usl.c
@@ -1,4 +1,4 @@
-/* $NetBSD: wsdisplay_compat_usl.c,v 1.10 1999/10/19 00:03:18 mycroft Exp $ */
+/* $NetBSD: wsdisplay_compat_usl.c,v 1.11 1999/12/06 18:52:23 drochner Exp $ */
 
 /*
  * Copyright (c) 1998
@@ -172,6 +172,10 @@ usl_detachproc(cookie, waitok, callback, cbarg)
 	if (!usl_sync_check(sd))
 		return (0);
 
+	/* we really need a callback */
+	if (!callback)
+		return (EINVAL);
+
 	/*
 	 * Normally, this is called from the controlling process.
 	 * Is is supposed to reply with a VT_RELDISP ioctl(), so
@@ -238,6 +242,10 @@ usl_attachproc(cookie, waitok, callback, cbarg)
 	if (!usl_sync_check(sd))
 		return (0);
 
+	/* we really need a callback */
+	if (!callback)
+		return (EINVAL);
+
 	sd->s_callback = callback;
 	sd->s_cbarg = cbarg;
 	sd->s_flags |= SF_ATTACHPENDING;
diff --git a/sys/dev/wscons/wsdisplayvar.h b/sys/dev/wscons/wsdisplayvar.h
index 32fc11afa88b..0f2ad5e3151b 100644
--- a/sys/dev/wscons/wsdisplayvar.h
+++ b/sys/dev/wscons/wsdisplayvar.h
@@ -1,4 +1,4 @@
-/* $NetBSD: wsdisplayvar.h,v 1.13 1999/10/19 00:03:18 mycroft Exp $ */
+/* $NetBSD: wsdisplayvar.h,v 1.14 1999/12/06 18:52:23 drochner Exp $ */
 
 /*
  * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
@@ -107,7 +107,8 @@ struct wsdisplay_accessops {
 	int	(*alloc_screen) __P((void *, const struct wsscreen_descr *,
 				     void **, int *, int *, long *));
 	void	(*free_screen) __P((void *, void *));
-	void	(*show_screen) __P((void *, void *));
+	int	(*show_screen) __P((void *, void *, int,
+				    void (*) (void *, int, int), void *));
 	int	(*load_font) __P((void *, void *, struct wsdisplay_font *));
 };