2 files changed, 15 insertions, 4 deletions

diff --git a/sys/dev/mpt/mpt.h b/sys/dev/mpt/mpt.h
index b347a0b19d30..4671521f1285 100644
--- a/sys/dev/mpt/mpt.h
+++ b/sys/dev/mpt/mpt.h
@@ -496,7 +496,8 @@ struct mpt_softc {
 	uint32_t		mpt_pers_mask;
 	uint32_t
 		unit		: 8,
-				: 3,
+				: 2,
+		msi_enable	: 1,
 		twildcard	: 1,
 		tenabled	: 1,
 		do_cfg_role	: 1,
diff --git a/sys/dev/mpt/mpt_pci.c b/sys/dev/mpt/mpt_pci.c
index 03b267a89cc8..58532f4f05c7 100644
--- a/sys/dev/mpt/mpt_pci.c
+++ b/sys/dev/mpt/mpt_pci.c
@@ -326,6 +326,8 @@ mpt_set_options(struct mpt_softc *mpt)
 		}
 		mpt->do_cfg_role = 1;
 	}
+
+	mpt->msi_enable = 0;
 }
 #else
 static void
@@ -350,6 +352,13 @@ mpt_set_options(struct mpt_softc *mpt)
 		mpt->cfg_role = tval;
 		mpt->do_cfg_role = 1;
 	}
+
+	tval = 0;
+	mpt->msi_enable = 1;
+	if (resource_int_value(device_get_name(mpt->dev),
+	    device_get_unit(mpt->dev), "msi_enable", &tval) == 0 && tval == 1) {
+		mpt->msi_enable = 1;
+	}
 }
 #endif
 
@@ -512,12 +521,13 @@ mpt_pci_attach(device_t dev)
 
 	/* Get a handle to the interrupt */
 	iqd = 0;
-	if (pci_msi_count(dev) == 1) {
+	if (mpt->msi_enable && pci_msi_count(dev) == 1) {
 		mpt->pci_msi_count = 1;
-		if (pci_alloc_msi(dev, &mpt->pci_msi_count) == 0)
+		if (pci_alloc_msi(dev, &mpt->pci_msi_count) == 0) {
 			iqd = 1;
-		else
+		} else {
 			mpt->pci_msi_count = 0;
+		}
 	}	
 	mpt->pci_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &iqd,
 	    RF_ACTIVE | RF_SHAREABLE);