diff --git a/sys/amd64/vmm/amd/amdiommu.c b/sys/amd64/vmm/amd/amdiommu.c
index 4ded23dff003..5eed6ce849cc 100644
--- a/sys/amd64/vmm/amd/amdiommu.c
+++ b/sys/amd64/vmm/amd/amdiommu.c
@@ -1,185 +1,185 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2021 The FreeBSD Fondation
  *
  * Portions of this software were developed by Ka Ho Ng
  * under sponsorship from the FreeBSD Foundation.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/bus.h>
 #include <sys/kernel.h>
 #include <sys/module.h>
 #include <sys/rman.h>
 
 #include <dev/pci/pcireg.h>
 #include <dev/pci/pcivar.h>
 
 #include "amdvi_priv.h"
 #include "ivhd_if.h"
 
 struct amdiommu_softc {
 	struct resource *event_res;	/* Event interrupt resource. */
 	void   		*event_tag;	/* Event interrupt tag. */
 	int		event_rid;
 };
 
 static int	amdiommu_probe(device_t);
 static int	amdiommu_attach(device_t);
 static int	amdiommu_detach(device_t);
 static int	ivhd_setup_intr(device_t, driver_intr_t, void *,
 		    const char *);
 static int	ivhd_teardown_intr(device_t);
 
 static device_method_t amdiommu_methods[] = {
 	/* device interface */
 	DEVMETHOD(device_probe,			amdiommu_probe),
 	DEVMETHOD(device_attach,		amdiommu_attach),
 	DEVMETHOD(device_detach,		amdiommu_detach),
 	DEVMETHOD(ivhd_setup_intr,		ivhd_setup_intr),
 	DEVMETHOD(ivhd_teardown_intr,		ivhd_teardown_intr),
 	DEVMETHOD_END
 };
 static driver_t amdiommu_driver = {
 	"amdiommu",
 	amdiommu_methods,
 	sizeof(struct amdiommu_softc),
 };
 
 static int
 amdiommu_probe(device_t dev)
 {
 	int error;
 	int capoff;
 
 	/*
 	 * Check base class and sub-class
 	 */
 	if (pci_get_class(dev) != PCIC_BASEPERIPH ||
 	    pci_get_subclass(dev) != PCIS_BASEPERIPH_IOMMU)
 		return (ENXIO);
 
 	/*
 	 * A IOMMU capability block carries a 0Fh capid.
 	 */
 	error = pci_find_cap(dev, PCIY_SECDEV, &capoff);
 	if (error)
 		return (ENXIO);
 
 	/*
 	 * bit [18:16] == 011b indicates the capability block is IOMMU
 	 * capability block. If the field is not set to 011b, bail out.
 	 */
 	if ((pci_read_config(dev, capoff + 2, 2) & 0x7) != 0x3)
 		return (ENXIO);
 
 	return (BUS_PROBE_SPECIFIC);
 }
 
 static int
 amdiommu_attach(device_t dev)
 {
 
 	device_set_desc(dev, "AMD-Vi/IOMMU PCI function");
 	return (0);
 }
 
 static int
 amdiommu_detach(device_t dev)
 {
 
 	return (0);
 }
 
 static int
 ivhd_setup_intr(device_t dev, driver_intr_t handler, void *arg,
     const char *desc)
 {
 	struct amdiommu_softc *sc;
 	int error, msicnt;
 
 	sc = device_get_softc(dev);
 	msicnt = 1;
 	if (sc->event_res != NULL)
 		panic("%s is called without intr teardown", __func__);
 	sc->event_rid = 1;
 
 	error = pci_alloc_msi(dev, &msicnt);
 	if (error) {
 		device_printf(dev, "Couldn't find event MSI IRQ resource.\n");
 		return (ENOENT);
 	}
 
 	sc->event_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
 	    &sc->event_rid, RF_ACTIVE);
 	if (sc->event_res == NULL) {
 		device_printf(dev, "Unable to allocate event INTR resource.\n");
 		error = ENOMEM;
 		goto fail;
 	}
 
 	error = bus_setup_intr(dev, sc->event_res, INTR_TYPE_MISC | INTR_MPSAFE,
 	    NULL, handler, arg, &sc->event_tag);
 	if (error) {
 		device_printf(dev, "Fail to setup event intr\n");
 		goto fail;
 	}
 
 	bus_describe_intr(dev, sc->event_res, sc->event_tag, "%s", desc);
 	return (0);
 
 fail:
 	ivhd_teardown_intr(dev);
 	return (error);
 }
 
 static int
 ivhd_teardown_intr(device_t dev)
 {
 	struct amdiommu_softc *sc;
 
 	sc = device_get_softc(dev);
 
-	if (sc->event_res != NULL) {
+	if (sc->event_tag != NULL) {
 		bus_teardown_intr(dev, sc->event_res, sc->event_tag);
 		sc->event_tag = NULL;
 	}
 	if (sc->event_res != NULL) {
 		bus_release_resource(dev, SYS_RES_IRQ, sc->event_rid,
 		    sc->event_res);
 		sc->event_res = NULL;
 	}
 	pci_release_msi(dev);
 	return (0);
 }
 
 static devclass_t amdiommu_devclass;
 
 /* This driver has to be loaded before ivhd */
 DRIVER_MODULE(amdiommu, pci, amdiommu_driver, amdiommu_devclass, 0, 0);
 MODULE_DEPEND(amdiommu, pci, 1, 1, 1);