Index: dev/pci/pci.c
===================================================================
--- dev/pci/pci.c	(revision 189044)
+++ dev/pci/pci.c	(working copy)
@@ -2864,6 +2864,8 @@
 			}
 			mte->mte_handlers++;
 		}
+		/* Disable INTx if we are using MSI/MSIX */
+		pci_set_command_bit(dev, child, PCIM_CMD_INTxDIS);
 	bad:
 		if (error) {
 			(void)bus_generic_teardown_intr(dev, child, irq,
@@ -2918,6 +2920,8 @@
 			if (mte->mte_handlers == 0)
 				pci_mask_msix(child, rid - 1);
 		}
+		/* Restore INTx capability for MSI/MSIX */
+		pci_clear_command_bit(dev, child, PCIM_CMD_INTxDIS);
 	}
 	error = bus_generic_teardown_intr(dev, child, irq, cookie);
 	if (device_get_parent(child) == dev && rid > 0)
Index: dev/pci/pcireg.h
===================================================================
--- dev/pci/pcireg.h	(revision 189044)
+++ dev/pci/pcireg.h	(working copy)
@@ -60,6 +60,7 @@
 #define	PCIM_CMD_PERRESPEN	0x0040
 #define	PCIM_CMD_SERRESPEN	0x0100
 #define	PCIM_CMD_BACKTOBACK	0x0200
+#define	PCIM_CMD_INTxDIS	0x0400
 #define	PCIR_STATUS	0x06
 #define	PCIM_STATUS_CAPPRESENT	0x0010
 #define	PCIM_STATUS_66CAPABLE	0x0020