Index: acpi_ibm.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/acpi_support/acpi_ibm.c,v
retrieving revision 1.14.2.2
diff -u -r1.14.2.2 acpi_ibm.c
--- acpi_ibm.c	29 Oct 2009 15:13:50 -0000	1.14.2.2
+++ acpi_ibm.c	4 Jan 2010 12:04:21 -0000
@@ -252,6 +252,7 @@
 static int	acpi_ibm_probe(device_t dev);
 static int	acpi_ibm_attach(device_t dev);
 static int	acpi_ibm_detach(device_t dev);
+static int	acpi_ibm_resume(device_t dev);
 
 static void	ibm_led(void *softc, int onoff);
 static void	ibm_led_task(struct acpi_ibm_softc *sc, int pending __unused);
@@ -270,6 +271,7 @@
 	DEVMETHOD(device_probe, acpi_ibm_probe),
 	DEVMETHOD(device_attach, acpi_ibm_attach),
 	DEVMETHOD(device_detach, acpi_ibm_detach),
+	DEVMETHOD(device_resume, acpi_ibm_resume),
 
 	{0, 0}
 };
@@ -435,6 +437,34 @@
 }
 
 static int
+acpi_ibm_resume(device_t dev)
+{
+	struct acpi_ibm_softc *sc = device_get_softc(dev);
+
+	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
+
+	ACPI_SERIAL_BEGIN(ibm);
+	for (int i = 0; acpi_ibm_sysctls[i].name != NULL; i++) {
+		int val;
+
+		if ((acpi_ibm_sysctls[i].access & CTLFLAG_RD) == 0) {
+			continue;
+		}
+
+		val = acpi_ibm_sysctl_get(sc, i);
+
+		if ((acpi_ibm_sysctls[i].access & CTLFLAG_WR) == 0) {
+			continue;
+		}
+
+		acpi_ibm_sysctl_set(sc, i, val);
+	}
+	ACPI_SERIAL_END(ibm);
+
+	return (0);
+}
+
+static int
 acpi_ibm_eventmask_set(struct acpi_ibm_softc *sc, int val)
 {
 	ACPI_OBJECT		arg[2];