e1000e: Fix irq_synchronize in MSI-X case

Based on original patch/work from Jean Delvare <jdelvare@suse.de>
Synchronize all IRQs when in MSI-X IRQ mode.

Jean's original patch hard coded the sync with the 3 possible vectors,
this patch incorporates more flexibility for the future and aligns
with how igb stores the number of vectors into the adapter structure.

CC: Jean Delvare <jdelvare@suse.de>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Acked-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000e/e1000.h

@@ -348,6 +348,7 @@ struct e1000_adapter {
 	u32 test_icr;
 
 	u32 msg_enable;
+	unsigned int num_vectors;
 	struct msix_entry *msix_entries;
 	int int_mode;
 	u32 eiac_mask;

drivers/net/e1000e/netdev.c

@@ -1785,26 +1785,26 @@ void e1000e_reset_interrupt_capability(struct e1000_adapter *adapter)
 void e1000e_set_interrupt_capability(struct e1000_adapter *adapter)
 {
 	int err;
-	int numvecs, i;
-
+	int i;
 
 	switch (adapter->int_mode) {
 	case E1000E_INT_MODE_MSIX:
 		if (adapter->flags & FLAG_HAS_MSIX) {
-			numvecs = 3; /* RxQ0, TxQ0 and other */
-			adapter->msix_entries = kcalloc(numvecs,
+			adapter->num_vectors = 3; /* RxQ0, TxQ0 and other */
+			adapter->msix_entries = kcalloc(adapter->num_vectors,
 						      sizeof(struct msix_entry),
 						      GFP_KERNEL);
 			if (adapter->msix_entries) {
-				for (i = 0; i < numvecs; i++)
+				for (i = 0; i < adapter->num_vectors; i++)
 					adapter->msix_entries[i].entry = i;
 
 				err = pci_enable_msix(adapter->pdev,
 						      adapter->msix_entries,
-						      numvecs);
-				if (err == 0)
+						      adapter->num_vectors);
+				if (err == 0) {
 					return;
 				}
+			}
 			/* MSI-X failed, so fall through and try MSI */
 			e_err("Failed to initialize MSI-X interrupts.  "
 			      "Falling back to MSI interrupts.\n");
@@ -1825,6 +1825,9 @@ void e1000e_set_interrupt_capability(struct e1000_adapter *adapter)
 		/* Don't do anything; this is the system default */
 		break;
 	}
+
+	/* store the number of vectors being used */
+	adapter->num_vectors = 1;
 }
 
 /**
@@ -1946,7 +1949,14 @@ static void e1000_irq_disable(struct e1000_adapter *adapter)
 	if (adapter->msix_entries)
 		ew32(EIAC_82574, 0);
 	e1e_flush();
+
+	if (adapter->msix_entries) {
+		int i;
+		for (i = 0; i < adapter->num_vectors; i++)
+			synchronize_irq(adapter->msix_entries[i].vector);
+	} else {
 		synchronize_irq(adapter->pdev->irq);
+	}
 }
 
 /**