diff --git a/sys/dev/firewire/fwohci.c b/sys/dev/firewire/fwohci.c
index f3ca25679a1c..b007f7646a77 100644
--- a/sys/dev/firewire/fwohci.c
+++ b/sys/dev/firewire/fwohci.c
@@ -584,6 +584,11 @@ fwohci_init(struct fwohci_softc *sc, device_t dev)
 	device_printf(dev, "OHCI version %x.%x (ROM=%d)\n",
 			(reg>>16) & 0xff, reg & 0xff, (reg>>24) & 1);
 
+	if (((reg>>16) & 0xff) < 1) {
+		device_printf(dev, "invalid OHCI version\n");
+		return (ENXIO);
+	}
+
 /* Available Isochrounous DMA channel probe */
 	OWRITE(sc, OHCI_IT_MASK, 0xffffffff);
 	OWRITE(sc, OHCI_IR_MASK, 0xffffffff);
@@ -1690,7 +1695,8 @@ fwohci_stop(struct fwohci_softc *sc, device_t dev)
 			| OHCI_INT_DMA_ARRQ | OHCI_INT_DMA_ARRS 
 			| OHCI_INT_PHY_BUS_R);
 
-	fw_drain_txq(&sc->fc);
+	if (sc->fc.arq !=0 && sc->fc.arq->maxq > 0)
+		fw_drain_txq(&sc->fc);
 
 /* XXX Link down?  Bus reset? */
 	return 0;
diff --git a/sys/dev/firewire/fwohci_pci.c b/sys/dev/firewire/fwohci_pci.c
index 0ac6b0040374..513343ae97ee 100644
--- a/sys/dev/firewire/fwohci_pci.c
+++ b/sys/dev/firewire/fwohci_pci.c
@@ -346,8 +346,14 @@ fwohci_pci_detach(device_t self)
 
 	s = splfw();
 
-	fwohci_stop(sc, self);
+	if (sc->bsr)
+		fwohci_stop(sc, self);
+
 	bus_generic_detach(self);
+	if (sc->fc.bdev) {
+		device_delete_child(self, sc->fc.bdev);
+		sc->fc.bdev = NULL;
+	}
 
 	/* disable interrupts that might have been switched on */
 	if (sc->bst && sc->bsh)
@@ -366,11 +372,6 @@ fwohci_pci_detach(device_t self)
 		sc->ih = NULL;
 	}
 
-	if (sc->fc.bdev) {
-		device_delete_child(self, sc->fc.bdev);
-		sc->fc.bdev = NULL;
-	}
-
 	if (sc->irq_res) {
 		bus_release_resource(self, SYS_RES_IRQ, 0, sc->irq_res);
 		sc->irq_res = NULL;