Index: sys/arch/x86/include/acpi_machdep.h
===================================================================
RCS file: /home/joerg/repo/netbsd/src/sys/arch/x86/include/acpi_machdep.h,v
retrieving revision 1.5
diff -u -p -r1.5 acpi_machdep.h
--- sys/arch/x86/include/acpi_machdep.h	14 Mar 2009 13:54:28 -0000	1.5
+++ sys/arch/x86/include/acpi_machdep.h	16 Jul 2010 20:09:42 -0000
@@ -73,3 +73,4 @@ void		acpi_md_OsEnableInterrupt(void);
 int		acpi_md_sleep(int);
 void		acpi_md_sleep_init(void);
 void		acpi_md_callback(void);
+void		acpi_mi_callback(void);
Index: sys/dev/acpi/acpi.c
===================================================================
RCS file: /home/joerg/repo/netbsd/src/sys/dev/acpi/acpi.c,v
retrieving revision 1.206
diff -u -p -r1.206 acpi.c
--- sys/dev/acpi/acpi.c	10 Jul 2010 13:08:09 -0000	1.206
+++ sys/dev/acpi/acpi.c	16 Jul 2010 20:10:19 -0000
@@ -474,20 +474,7 @@ acpi_attach(device_t parent, device_t se
 		acpi_osd_debugger();
 #endif
 
-#define ACPI_ENABLE_PHASE1 \
-    (ACPI_NO_HANDLER_INIT | ACPI_NO_EVENT_INIT)
-#define ACPI_ENABLE_PHASE2 \
-    (ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE | \
-     ACPI_NO_ADDRESS_SPACE_INIT)
-
-	rv = AcpiEnableSubsystem(ACPI_ENABLE_PHASE1);
-
-	if (ACPI_FAILURE(rv))
-		goto fail;
-
-	acpi_md_callback();
-
-	rv = AcpiEnableSubsystem(ACPI_ENABLE_PHASE2);
+	rv = AcpiEnableSubsystem(ACPI_FULL_INITIALIZATION);
 
 	if (ACPI_FAILURE(rv))
 		goto fail;
@@ -517,6 +504,9 @@ acpi_attach(device_t parent, device_t se
 	if (ACPI_FAILURE(rv))
 		goto fail;
 
+	acpi_md_callback();
+	acpi_mi_callback();
+
 	acpi_active = 1;
 
 	/* Show SCI interrupt. */
Index: sys/dev/acpi/acpica/OsdInterrupt.c
===================================================================
RCS file: /home/joerg/repo/netbsd/src/sys/dev/acpi/acpica/OsdInterrupt.c,v
retrieving revision 1.8
diff -u -p -r1.8 OsdInterrupt.c
--- sys/dev/acpi/acpica/OsdInterrupt.c	18 Aug 2009 16:41:02 -0000	1.8
+++ sys/dev/acpi/acpica/OsdInterrupt.c	16 Jul 2010 20:09:42 -0000
@@ -69,9 +69,12 @@ struct acpi_interrupt_handler {
 	LIST_ENTRY(acpi_interrupt_handler) aih_list;
 	UINT32 aih_intrnum;
 	ACPI_OSD_HANDLER aih_func;
+	void *aih_context;
 	void *aih_ih;
+	int aih_deferred;
 };
 
+static int pre_acpi_md_callback = 1;
 static LIST_HEAD(, acpi_interrupt_handler) acpi_interrupt_list =
     LIST_HEAD_INITIALIZER(&acpi_interrupt_list);
 
@@ -100,6 +103,15 @@ AcpiOsInstallInterruptHandler(UINT32 Int
 
 	aih->aih_intrnum = InterruptNumber;
 	aih->aih_func = ServiceRoutine;
+	aih->aih_context = Context;
+	aih->aih_deferred = pre_acpi_md_callback;
+
+	if (pre_acpi_md_callback) {
+		mutex_enter(&acpi_interrupt_list_mtx);
+		LIST_INSERT_HEAD(&acpi_interrupt_list, aih, aih_list);
+		mutex_exit(&acpi_interrupt_list_mtx);
+		return AE_OK;
+	}
 
 	rv = acpi_md_OsInstallInterruptHandler(InterruptNumber,
 	    ServiceRoutine, Context, &aih->aih_ih);
@@ -113,6 +125,27 @@ AcpiOsInstallInterruptHandler(UINT32 Int
 	return rv;
 }
 
+void
+acpi_mi_callback(void)
+{
+	struct acpi_interrupt_handler *aih;
+	ACPI_STATUS rv;
+
+	mutex_enter(&acpi_interrupt_list_mtx);
+
+	LIST_FOREACH(aih, &acpi_interrupt_list, aih_list) {
+		rv = acpi_md_OsInstallInterruptHandler(aih->aih_intrnum,
+		    aih->aih_func, aih->aih_context, &aih->aih_ih);
+		if (rv != AE_OK)
+			panic("Unable to setup deferred ACPI interrupt");
+		aih->aih_deferred = 0;
+	}
+
+	pre_acpi_md_callback = 0;
+
+	mutex_exit(&acpi_interrupt_list_mtx);
+}
+
 /*
  * AcpiOsRemoveInterruptHandler:
  *
@@ -135,7 +168,8 @@ AcpiOsRemoveInterruptHandler(UINT32 Inte
 		    aih->aih_func == ServiceRoutine) {
 			LIST_REMOVE(aih, aih_list);
 			mutex_exit(&acpi_interrupt_list_mtx);
-			acpi_md_OsRemoveInterruptHandler(aih->aih_ih);
+			if (aih->aih_deferred == 0)
+				acpi_md_OsRemoveInterruptHandler(aih->aih_ih);
 			free(aih, M_ACPI);
 			return AE_OK;
 		}