3 files changed, 61 insertions, 5 deletions

diff --git a/sys/dev/atkbdc/atkbd.c b/sys/dev/atkbdc/atkbd.c
index eedc469a43c71..99877874889fe 100644
--- a/sys/dev/atkbdc/atkbd.c
+++ b/sys/dev/atkbdc/atkbd.c
@@ -282,11 +282,12 @@ atkbd_configure(int flags)
 	int arg[2];
 	int i;
 
-	/* probe the keyboard controller */
-	atkbdc_configure();
-
-	/* if the driver is disabled, unregister the keyboard if any */
-	if (resource_disabled("atkbd", ATKBD_DEFAULT)) {
+	/*
+	 * Probe the keyboard controller, if not present or if the driver
+	 * is disabled, unregister the keyboard if any.
+	 */
+	if (atkbdc_configure() != 0 ||
+	    resource_disabled("atkbd", ATKBD_DEFAULT)) {
 		i = kbd_find_keyboard(ATKBD_DRIVER_NAME, ATKBD_DEFAULT);
 		if (i >= 0) {
 			kbd = kbd_get_keyboard(i);
diff --git a/sys/dev/atkbdc/atkbdc.c b/sys/dev/atkbdc/atkbdc.c
index b32a21819b476..247a116c45230 100644
--- a/sys/dev/atkbdc/atkbdc.c
+++ b/sys/dev/atkbdc/atkbdc.c
@@ -153,6 +153,10 @@ atkbdc_configure(void)
 	bus_space_tag_t tag;
 	bus_space_handle_t h0;
 	bus_space_handle_t h1;
+#if defined(__i386__)
+	volatile int i;
+	register_t flags;
+#endif
 #ifdef __sparc64__
 	char name[32];
 	phandle_t chosen, node;
@@ -219,6 +223,26 @@ atkbdc_configure(void)
 	h1 = (bus_space_handle_t)port1;
 #endif
 #endif
+
+#if defined(__i386__)
+	/*
+	 * Check if we really have AT keyboard controller. Poll status
+	 * register until we get "all clear" indication. If no such
+	 * indication comes, it probably means that there is no AT
+	 * keyboard controller present. Give up in such case. Check relies
+	 * on the fact that reading from non-existing in/out port returns
+	 * 0xff on i386. May or may not be true on other platforms.
+	 */
+	flags = intr_disable();
+	for (i = 0; i != 65535; i++) {
+		if ((bus_space_read_1(tag, h1, 0) & 0x2) == 0)
+			break;
+	}
+	intr_restore(flags);
+	if (i == 65535)
+                return ENXIO;
+#endif
+
 	return atkbdc_setup(atkbdc_softc[0], tag, h0, h1);
 }
 
diff --git a/sys/dev/atkbdc/atkbdc_isa.c b/sys/dev/atkbdc/atkbdc_isa.c
index deeb7a0e49616..96abfb5a15616 100644
--- a/sys/dev/atkbdc/atkbdc_isa.c
+++ b/sys/dev/atkbdc/atkbdc_isa.c
@@ -93,6 +93,12 @@ atkbdc_isa_probe(device_t dev)
 	u_long		count;
 	int		error;
 	int		rid;
+#if defined(__i386__)
+	bus_space_tag_t	tag;
+	bus_space_handle_t ioh1;
+	volatile int	i;
+	register_t	flags;
+#endif
 
 	/* check PnP IDs */
 	if (ISA_PNP_PROBE(device_get_parent(dev), dev, atkbdc_ids) == ENXIO)
@@ -127,6 +133,31 @@ atkbdc_isa_probe(device_t dev)
 		bus_release_resource(dev, SYS_RES_IOPORT, 0, port0);
 		return ENXIO;
 	}
+
+#if defined(__i386__)
+	/*
+	 * Check if we really have AT keyboard controller. Poll status
+	 * register until we get "all clear" indication. If no such
+	 * indication comes, it probably means that there is no AT
+	 * keyboard controller present. Give up in such case. Check relies
+	 * on the fact that reading from non-existing in/out port returns
+	 * 0xff on i386. May or may not be true on other platforms.
+	 */
+	tag = rman_get_bustag(port0);
+	ioh1 = rman_get_bushandle(port1);
+	flags = intr_disable();
+	for (i = 0; i != 65535; i++) {
+		if ((bus_space_read_1(tag, ioh1, 0) & 0x2) == 0)
+			break;
+	}
+	intr_restore(flags);
+	if (i == 65535) {
+		bus_release_resource(dev, SYS_RES_IOPORT, 0, port0);
+		bus_release_resource(dev, SYS_RES_IOPORT, 1, port1);
+		return ENXIO;
+	}
+#endif
+
 	device_verbose(dev);
 
 	error = atkbdc_probe_unit(device_get_unit(dev), port0, port1);