Index: sys/dev/acpica/acpi.c
===================================================================
--- sys/dev/acpica/acpi.c	(revision 237459)
+++ sys/dev/acpica/acpi.c	(working copy)
@@ -1855,7 +1855,6 @@ acpi_probe_order(ACPI_HANDLE handle, int *order)
 static ACPI_STATUS
 acpi_probe_child(ACPI_HANDLE handle, UINT32 level, void *context, void **status)
 {
-    struct acpi_prw_data prw;
     ACPI_OBJECT_TYPE type;
     ACPI_HANDLE h;
     device_t bus, child;
@@ -1885,8 +1884,6 @@ acpi_probe_child(ACPI_HANDLE handle, UINT32 level,
 	    if (strcmp(handle_str, "\\_SB_") == 0 ||
 		strcmp(handle_str, "\\_TZ_") == 0)
 		break;
-	    if (acpi_parse_prw(handle, &prw) == 0)
-		AcpiSetupGpeForWake(handle, prw.gpe_handle, prw.gpe_bit);
 
 	    /*
 	     * Ignore devices that do not have a _HID or _CID.  They should
@@ -2834,7 +2831,6 @@ int
 acpi_wake_set_enable(device_t dev, int enable)
 {
     struct acpi_prw_data prw;
-    ACPI_STATUS status;
     int flags;
 
     /* Make sure the device supports waking the system and get the GPE. */
@@ -2842,23 +2838,10 @@ acpi_wake_set_enable(device_t dev, int enable)
 	return (ENXIO);
 
     flags = acpi_get_flags(dev);
-    if (enable) {
-	status = AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit,
-	    ACPI_GPE_ENABLE);
-	if (ACPI_FAILURE(status)) {
-	    device_printf(dev, "enable wake failed\n");
-	    return (ENXIO);
-	}
+    if (enable)
 	acpi_set_flags(dev, flags | ACPI_FLAG_WAKE_ENABLED);
-    } else {
-	status = AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit,
-	    ACPI_GPE_DISABLE);
-	if (ACPI_FAILURE(status)) {
-	    device_printf(dev, "disable wake failed\n");
-	    return (ENXIO);
-	}
+    else
 	acpi_set_flags(dev, flags & ~ACPI_FLAG_WAKE_ENABLED);
-    }
 
     return (0);
 }
@@ -2868,10 +2851,15 @@ acpi_wake_sleep_prep(ACPI_HANDLE handle, int sstat
 {
     struct acpi_prw_data prw;
     device_t dev;
+    ACPI_STATUS status;
 
     /* Check that this is a wake-capable device and get its GPE. */
     if (acpi_parse_prw(handle, &prw) != 0)
 	return (ENXIO);
+
+    status = AcpiSetupGpeForWake(handle, prw.gpe_handle, prw.gpe_bit);
+    if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS)
+	return (ENXIO);
     dev = acpi_get_device(handle);
 
     /*
@@ -2887,7 +2875,8 @@ acpi_wake_sleep_prep(ACPI_HANDLE handle, int sstat
 	    device_printf(dev, "wake_prep disabled wake for %s (S%d)\n",
 		acpi_name(handle), sstate);
     } else if (dev && (acpi_get_flags(dev) & ACPI_FLAG_WAKE_ENABLED) != 0) {
-	acpi_pwr_wake_enable(handle, 1);
+	AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit, ACPI_GPE_ENABLE);
+	acpi_pwr_wake_enable(handle, &prw, 1);
 	acpi_SetInteger(handle, "_PSW", 1);
 	if (bootverbose)
 	    device_printf(dev, "wake_prep enabled for %s (S%d)\n",
@@ -2923,8 +2912,9 @@ acpi_wake_run_prep(ACPI_HANDLE handle, int sstate)
 	if (bootverbose)
 	    device_printf(dev, "run_prep re-enabled %s\n", acpi_name(handle));
     } else {
+	AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit, ACPI_GPE_DISABLE);
 	acpi_SetInteger(handle, "_PSW", 0);
-	acpi_pwr_wake_enable(handle, 0);
+	acpi_pwr_wake_enable(handle, &prw, 0);
 	if (bootverbose)
 	    device_printf(dev, "run_prep cleaned up for %s\n",
 		acpi_name(handle));
Index: sys/dev/acpica/acpi_button.c
===================================================================
--- sys/dev/acpica/acpi_button.c	(revision 237459)
+++ sys/dev/acpica/acpi_button.c	(working copy)
@@ -165,9 +165,10 @@ acpi_button_attach(device_t dev)
     }
 
     /* Enable the GPE for wake/runtime. */
-    acpi_wake_set_enable(dev, 1);
-    if (acpi_parse_prw(sc->button_handle, &prw) == 0)
+    if (acpi_parse_prw(sc->button_handle, &prw) == 0) {
+	acpi_set_flags(dev, ACPI_FLAG_WAKE_ENABLED);
 	AcpiEnableGpe(prw.gpe_handle, prw.gpe_bit);
+    }
 
     return_VALUE (0);
 }
Index: sys/dev/acpica/acpi_lid.c
===================================================================
--- sys/dev/acpica/acpi_lid.c	(revision 237459)
+++ sys/dev/acpica/acpi_lid.c	(working copy)
@@ -116,9 +116,10 @@ acpi_lid_attach(device_t dev)
 			     acpi_lid_notify_handler, sc);
 
     /* Enable the GPE for wake/runtime. */
-    acpi_wake_set_enable(dev, 1);
-    if (acpi_parse_prw(sc->lid_handle, &prw) == 0)
+    if (acpi_parse_prw(sc->lid_handle, &prw) == 0) {
+	acpi_set_flags(dev, ACPI_FLAG_WAKE_ENABLED);
 	AcpiEnableGpe(prw.gpe_handle, prw.gpe_bit);
+    }
 
     return (0);
 }
Index: sys/dev/acpica/acpi_powerres.c
===================================================================
--- sys/dev/acpica/acpi_powerres.c	(revision 237459)
+++ sys/dev/acpica/acpi_powerres.c	(working copy)
@@ -502,16 +502,16 @@ out:
 
 /* Enable or disable a power resource for wake */
 ACPI_STATUS
-acpi_pwr_wake_enable(ACPI_HANDLE consumer, int enable)
+acpi_pwr_wake_enable(ACPI_HANDLE consumer, struct acpi_prw_data *prw,
+    int enable)
 {
     ACPI_STATUS status;
     struct acpi_powerconsumer *pc;
-    struct acpi_prw_data prw;
     int i;
 
     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
 
-    if (consumer == NULL)
+    if (consumer == NULL || prw == NULL)
 	return (AE_BAD_PARAMETER);
 
     ACPI_SERIAL_BEGIN(powerres);
@@ -522,16 +522,13 @@ ACPI_STATUS
 	    panic("acpi wake added power consumer but can't find it");
     }
 
-    status = AE_OK;
-    if (acpi_parse_prw(consumer, &prw) != 0)
-	goto out;
-    for (i = 0; i < prw.power_res_count; i++)
+    for (i = 0; i < prw->power_res_count; i++)
 	if (enable)
-	    acpi_pwr_reference_resource(&prw.power_res[i], pc);
+	    acpi_pwr_reference_resource(&prw->power_res[i], pc);
 	else
 	    acpi_pwr_dereference_resource(pc);
 
-    if (prw.power_res_count > 0)
+    if (prw->power_res_count > 0)
 	acpi_pwr_switch_power();
 
 out:
Index: sys/dev/acpica/acpivar.h
===================================================================
--- sys/dev/acpica/acpivar.h	(revision 237459)
+++ sys/dev/acpica/acpivar.h	(working copy)
@@ -403,7 +403,8 @@ EVENTHANDLER_DECLARE(acpi_sleep_event, acpi_event_
 EVENTHANDLER_DECLARE(acpi_wakeup_event, acpi_event_handler_t);
 
 /* Device power control. */
-ACPI_STATUS	acpi_pwr_wake_enable(ACPI_HANDLE consumer, int enable);
+ACPI_STATUS	acpi_pwr_wake_enable(ACPI_HANDLE consumer,
+		    struct acpi_prw_data *, int enable);
 ACPI_STATUS	acpi_pwr_switch_consumer(ACPI_HANDLE consumer, int state);
 int		acpi_device_pwr_for_sleep(device_t bus, device_t dev,
 		    int *dstate);