Make the various driver MSIX setup routines fallback to MSI more

gracefully. This change was suggested by Marius Strobl, thank you.

PR: kern/181016
MFC after: ASAP

2 files changed, 26 insertions, 27 deletions

diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index 9ac585aca2c5..ca4aa660ad9d 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -2415,29 +2415,24 @@ ixgbe_setup_msix(struct adapter *adapter)
 		goto msi;
 
 	/* First try MSI/X */
+	msgs = pci_msix_count(dev); 
+	if (msgs == 0)
+		goto msi;
 	rid = PCIR_BAR(MSIX_82598_BAR);
 	adapter->msix_mem = bus_alloc_resource_any(dev,
 	    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		rid += 4;	/* 82599 maps in higher BAR */
 		adapter->msix_mem = bus_alloc_resource_any(dev,
 		    SYS_RES_MEMORY, &rid, RF_ACTIVE);
 	}
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		/* May not be enabled */
 		device_printf(adapter->dev,
 		    "Unable to map MSIX table \n");
 		goto msi;
 	}
 
-	msgs = pci_msix_count(dev); 
-	if (msgs == 0) { /* system has msix disabled */
-		bus_release_resource(dev, SYS_RES_MEMORY,
-		    rid, adapter->msix_mem);
-		adapter->msix_mem = NULL;
-		goto msi;
-	}
-
 	/* Figure out a reasonable auto config value */
 	queues = (mp_ncpus > (msgs-1)) ? (msgs-1) : mp_ncpus;
 
@@ -2459,21 +2454,27 @@ ixgbe_setup_msix(struct adapter *adapter)
 		    "MSIX Configuration Problem, "
 		    "%d vectors but %d queues wanted!\n",
 		    msgs, want);
-		return (0); /* Will go to Legacy setup */
+		goto msi;
 	}
-	if ((msgs) && pci_alloc_msix(dev, &msgs) == 0) {
+	if (pci_alloc_msix(dev, &msgs) == 0) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", msgs);
 		adapter->num_queues = queues;
 		return (msgs);
 	}
 msi:
-       	msgs = pci_msi_count(dev);
-       	if (msgs == 1 && pci_alloc_msi(dev, &msgs) == 0)
+       	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    rid, adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
+       	msgs = 1;
+       	if (pci_alloc_msi(dev, &msgs) == 0) {
                	device_printf(adapter->dev,"Using an MSI interrupt\n");
-	else
-               	device_printf(adapter->dev,"Using a Legacy interrupt\n");
-	return (msgs);
+		return (msgs);
+	}
+	device_printf(adapter->dev,"Using a Legacy interrupt\n");
+	return (0);
 }
 
 
diff --git a/sys/dev/ixgbe/ixv.c b/sys/dev/ixgbe/ixv.c
index e51cdb3066eb..20131aa41cb9 100644
--- a/sys/dev/ixgbe/ixv.c
+++ b/sys/dev/ixgbe/ixv.c
@@ -1686,37 +1686,35 @@ static int
 ixv_setup_msix(struct adapter *adapter)
 {
 	device_t dev = adapter->dev;
-	int rid, vectors, want = 2;
+	int rid, want;
 
 
 	/* First try MSI/X */
 	rid = PCIR_BAR(3);
 	adapter->msix_mem = bus_alloc_resource_any(dev,
 	    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		device_printf(adapter->dev,
 		    "Unable to map MSIX table \n");
 		goto out;
 	}
 
-	vectors = pci_msix_count(dev); 
-	if (vectors < 2) {
-		bus_release_resource(dev, SYS_RES_MEMORY,
-		    rid, adapter->msix_mem);
-		adapter->msix_mem = NULL;
-		goto out;
-	}
-
 	/*
 	** Want two vectors: one for a queue,
 	** plus an additional for mailbox.
 	*/
+	want = 2;
 	if (pci_alloc_msix(dev, &want) == 0) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", want);
 		return (want);
 	}
 out:
+       	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    rid, adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
 	device_printf(adapter->dev,"MSIX config error\n");
 	return (ENXIO);
 }