qlcnic: Support polling for mailbox events.

o When mailbox interrupt is disabled PF should be
  able to process request from VF. Enable polling
  for such cases.

Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index a79276d..247a9f9 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -3306,8 +3306,10 @@
 
 	qlcnic_detach(adapter);
 
-	if (qlcnic_83xx_check(adapter))
+	if (qlcnic_83xx_check(adapter)) {
 		qlcnic_83xx_free_mbx_intr(adapter);
+		qlcnic_83xx_enable_mbx_poll(adapter);
+	}
 
 	qlcnic_teardown_intr(adapter);
 	err = qlcnic_setup_intr(adapter, data);
@@ -3321,6 +3323,7 @@
 		/* register for NIC IDC AEN Events */
 		qlcnic_83xx_register_nic_idc_func(adapter, 1);
 		err = qlcnic_83xx_setup_mbx_intr(adapter);
+		qlcnic_83xx_disable_mbx_poll(adapter);
 		if (err) {
 			dev_err(&adapter->pdev->dev,
 				"failed to setup mbx interrupt\n");