Index: head/sys/dev/acpica/acpi.c
===================================================================
--- head/sys/dev/acpica/acpi.c
+++ head/sys/dev/acpica/acpi.c
@@ -2482,10 +2482,12 @@
 
 ACPI_STATUS
 acpi_EvaluateOSC(ACPI_HANDLE handle, uint8_t *uuid, int revision, int count,
-    uint32_t *caps)
+    uint32_t *caps_in, uint32_t *caps_out, bool query)
 {
-	ACPI_OBJECT arg[4];
+	ACPI_OBJECT arg[4], *ret;
 	ACPI_OBJECT_LIST arglist;
+	ACPI_BUFFER buf;
+	ACPI_STATUS status;
 
 	arglist.Pointer = arg;
 	arglist.Count = 4;
@@ -2497,9 +2499,25 @@
 	arg[2].Type = ACPI_TYPE_INTEGER;
 	arg[2].Integer.Value = count;
 	arg[3].Type = ACPI_TYPE_BUFFER;
-	arg[3].Buffer.Length = count * sizeof(*caps);
-	arg[3].Buffer.Pointer = (uint8_t *)caps;
-	return (AcpiEvaluateObject(handle, "_OSC", &arglist, NULL));
+	arg[3].Buffer.Length = count * sizeof(*caps_in);
+	arg[3].Buffer.Pointer = (uint8_t *)caps_in;
+	caps_in[0] = query ? 1 : 0;
+	buf.Pointer = NULL;
+	buf.Length = ACPI_ALLOCATE_BUFFER;
+	status = AcpiEvaluateObjectTyped(handle, "_OSC", &arglist, &buf,
+	    ACPI_TYPE_BUFFER);
+	if (ACPI_FAILURE(status))
+		return (status);
+	if (caps_out != NULL) {
+		ret = buf.Pointer;
+		if (ret->Buffer.Length != count * sizeof(*caps_out)) {
+			AcpiOsFree(buf.Pointer);
+			return (AE_BUFFER_OVERFLOW);
+		}
+		bcopy(ret->Buffer.Pointer, caps_out, ret->Buffer.Length);
+	}
+	AcpiOsFree(buf.Pointer);
+	return (status);
 }
 
 /*
Index: head/sys/dev/acpica/acpi_cpu.c
===================================================================
--- head/sys/dev/acpica/acpi_cpu.c
+++ head/sys/dev/acpica/acpi_cpu.c
@@ -388,9 +388,9 @@
      * Intel Processor Vendor-Specific ACPI Interface Specification.
      */
     if (sc->cpu_features) {
-	cap_set[0] = 0;
 	cap_set[1] = sc->cpu_features;
-	status = acpi_EvaluateOSC(sc->cpu_handle, cpu_oscuuid, 1, 2, cap_set);
+	status = acpi_EvaluateOSC(sc->cpu_handle, cpu_oscuuid, 1, 2, cap_set,
+	    cap_set, false);
 	if (ACPI_SUCCESS(status)) {
 	    if (cap_set[0] != 0)
 		device_printf(dev, "_OSC returned status %#x\n", cap_set[0]);
Index: head/sys/dev/acpica/acpi_pcib_acpi.c
===================================================================
--- head/sys/dev/acpica/acpi_pcib_acpi.c
+++ head/sys/dev/acpica/acpi_pcib_acpi.c
@@ -306,9 +306,6 @@
 		0x96, 0x57, 0x74, 0x41, 0xc0, 0x3d, 0xd7, 0x66
 	};
 
-	/* Query Support Flag */
-	cap_set[0] = 0;
-
 	/* Support Field: Extended PCI Config Space, MSI */
 	cap_set[1] = 0x11;
 
@@ -316,7 +313,7 @@
 	cap_set[2] = 0;
 
 	status = acpi_EvaluateOSC(sc->ap_handle, pci_host_bridge_uuid, 1,
-	    nitems(cap_set), cap_set);
+	    nitems(cap_set), cap_set, cap_set, false);
 	if (ACPI_FAILURE(status)) {
 		if (status == AE_NOT_FOUND)
 			return;
@@ -328,7 +325,6 @@
 	if (cap_set[0] != 0) {
 		device_printf(sc->ap_dev, "_OSC returned error %#x\n",
 		    cap_set[0]);
-		return;
 	}
 }
 
Index: head/sys/dev/acpica/acpivar.h
===================================================================
--- head/sys/dev/acpica/acpivar.h
+++ head/sys/dev/acpica/acpivar.h
@@ -336,7 +336,8 @@
 ACPI_STATUS	acpi_AppendBufferResource(ACPI_BUFFER *buf,
 		    ACPI_RESOURCE *res);
 ACPI_STATUS	acpi_EvaluateOSC(ACPI_HANDLE handle, uint8_t *uuid,
-		    int revision, int count, uint32_t *caps);
+		    int revision, int count, uint32_t *caps_in,
+		    uint32_t *caps_out, bool query);
 ACPI_STATUS	acpi_OverrideInterruptLevel(UINT32 InterruptNumber);
 ACPI_STATUS	acpi_SetIntrModel(int model);
 int		acpi_ReqSleepState(struct acpi_softc *sc, int state);