ixgbe: Return PCI_ERS_RESULT_DISCONNECT when bus is disabled

According to the "PCI Error Recovery" document, if after a recovery,
the bus is disabled, the error_detected function should return
PCI_ERS_RESULT_DISCONNECT. Actually ixgbe error_detected function is
always returning PCI_ERS_RESULT_NEED_RESET, even if the bus is in failure.
This patch just check if the bus is disabled and then returns
PCI_ERS_RESULT_DISCONNET.
Signed-off-by: NBreno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -5145,6 +5145,9 @@ static pci_ers_result_t ixgbe_io_error_detected(struct pci_dev *pdev,
 
 	netif_device_detach(netdev);
 
+	if (state == pci_channel_io_perm_failure)
+		return PCI_ERS_RESULT_DISCONNECT;
+
 	if (netif_running(netdev))
 		ixgbe_down(adapter);
 	pci_disable_device(pdev);