diff --git a/sys/dev/acpica/Osd/OsdInterrupt.c b/sys/dev/acpica/Osd/OsdInterrupt.c
index 3fb1e70685d..8233eca812b 100644
--- a/sys/dev/acpica/Osd/OsdInterrupt.c
+++ b/sys/dev/acpica/Osd/OsdInterrupt.c
@@ -218,3 +218,9 @@ acpi_OverrideInterruptLevel(UINT32 InterruptNumber)
 	InterruptOverride = InterruptNumber;
 	return_ACPI_STATUS (AE_OK);
 }
+
+UINT32
+acpi_GetSciInterrupt(void)
+{
+	return InterruptOverride ?: AcpiGbl_FADT.SciInterrupt;
+}
diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index 1be783c132f..09b956a0abe 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$");
 #endif
 #include <machine/resource.h>
 #include <machine/bus.h>
+#include <machine/intr_machdep.h>
 #include <sys/rman.h>
 #include <isa/isavar.h>
 #include <isa/pnpvar.h>
@@ -3050,20 +3051,12 @@ __do_sleep(struct acpi_softc *sc, int state)
 static void
 __do_s0ix(struct acpi_softc *sc)
 {
-	int *state;
+	intr_suspend();
+	intr_enable_src(acpi_GetSciInterrupt());
 
-	critical_enter();
+	acpi_cpu_idle_mwait(0);
 
-	state = (int *)PCPU_PTR(monitorbuf);
-	atomic_store_int(state, 1);
-
-	cpu_monitor(state, 0, 0);
-	if (atomic_load_int(state) == 1)
-		cpu_mwait(0, 0);
-
-	atomic_store_int(state, 0);
-
-	critical_exit();
+	intr_resume(false);
 }
 
 /*
@@ -3141,11 +3134,13 @@ acpi_EnterSleepState(struct acpi_softc *sc, int state)
     }
     slp_state = ACPI_SS_DEV_SUSPEND;
 
-    status = AcpiEnterSleepStatePrep(state);
-    if (ACPI_FAILURE(status)) {
-	device_printf(sc->acpi_dev, "AcpiEnterSleepStatePrep failed - %s\n",
-		      AcpiFormatException(status));
-	goto backout;
+    if (!prefer_s0ix(sc, state)) {
+	    status = AcpiEnterSleepStatePrep(state);
+	    if (ACPI_FAILURE(status)) {
+		    device_printf(sc->acpi_dev, "AcpiEnterSleepStatePrep failed - %s\n",
+			AcpiFormatException(status));
+		    goto backout;
+	    }
     }
     slp_state = ACPI_SS_SLP_PREP;
 
@@ -3196,7 +3191,7 @@ acpi_EnterSleepState(struct acpi_softc *sc, int state)
     }
     if (slp_state >= ACPI_SS_DEV_SUSPEND)
 	DEVICE_RESUME(root_bus);
-    if (slp_state >= ACPI_SS_SLP_PREP)
+    if (!prefer_s0ix(sc, state)&& (slp_state >= ACPI_SS_SLP_PREP))
 	AcpiLeaveSleepState(state);
 
     sc->acpi_next_sstate = 0;
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
index faf6c75424b..1c39e4bd830 100644
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -367,6 +367,7 @@ ACPI_STATUS	acpi_EvaluateOSC(ACPI_HANDLE handle, uint8_t *uuid,
 		    int revision, int count, uint32_t *caps_in,
 		    uint32_t *caps_out, bool query);
 ACPI_STATUS	acpi_OverrideInterruptLevel(UINT32 InterruptNumber);
+UINT32 		acpi_GetSciInterrupt(void);
 ACPI_STATUS	acpi_SetIntrModel(int model);
 int		acpi_ReqSleepState(struct acpi_softc *sc, int state);
 int		acpi_AckSleepState(struct apm_clone_data *clone, int error);
diff --git a/sys/x86/include/intr_machdep.h b/sys/x86/include/intr_machdep.h
index d9e7f881ffd..f4c5e3b19b5 100644
--- a/sys/x86/include/intr_machdep.h
+++ b/sys/x86/include/intr_machdep.h
@@ -162,6 +162,7 @@ int	intr_register_source(struct intsrc *isrc);
 int	intr_remove_handler(void *cookie);
 void	intr_resume(bool suspend_cancelled);
 void	intr_suspend(void);
+void 	intr_enable_src(u_int irq);
 void	intr_reprogram(void);
 void	intrcnt_add(const char *name, u_long **countp);
 void	nexus_add_irq(u_long irq);
diff --git a/sys/x86/x86/intr_machdep.c b/sys/x86/x86/intr_machdep.c
index 9f93ec96f83..0a64156678f 100644
--- a/sys/x86/x86/intr_machdep.c
+++ b/sys/x86/x86/intr_machdep.c
@@ -396,6 +396,17 @@ intr_suspend(void)
 	mtx_unlock(&intrpic_lock);
 }
 
+void
+intr_enable_src(u_int irq)
+{
+	struct intsrc *is;
+
+	sx_slock(&intrsrc_lock);
+	is = interrupt_sources[irq];
+	is->is_pic->pic_enable_source(is);
+	sx_sunlock(&intrsrc_lock);
+}
+
 static int
 intr_assign_cpu(void *arg, int cpu)
 {