net/mlx4_core: Implement pci_resume callback

BugLink: http://bugs.launchpad.net/bugs/1574697

Move resume related activities to a new pci_resume function instead of
performing them in mlx4_pci_slot_reset.  This change is needed to avoid
a hotplug during EEH recovery due to commit f2da4ccf ("powerpc/eeh:
More relaxed hotplug criterion").

Fixes: 2ba5fbd6 ('net/mlx4_core: Handle AER flow properly')
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit c12833ac)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -3879,45 +3879,53 @@ static pci_ers_result_t mlx4_pci_slot_reset(struct pci_dev *pdev)
 {
 	struct mlx4_dev_persistent *persist = pci_get_drvdata(pdev);
 	struct mlx4_dev	 *dev  = persist->dev;
-	struct mlx4_priv *priv = mlx4_priv(dev);
-	int               ret;
-	int nvfs[MLX4_MAX_PORTS + 1] = {0, 0, 0};
-	int total_vfs;
+	int err;
 
 	mlx4_err(dev, "mlx4_pci_slot_reset was called\n");
-	ret = pci_enable_device(pdev);
-	if (ret) {
-		mlx4_err(dev, "Can not re-enable device, ret=%d\n", ret);
+	err = pci_enable_device(pdev);
+	if (err) {
+		mlx4_err(dev, "Can not re-enable device, err=%d\n", err);
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
 
 	pci_set_master(pdev);
 	pci_restore_state(pdev);
 	pci_save_state(pdev);
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void mlx4_pci_resume(struct pci_dev *pdev)
+{
+	struct mlx4_dev_persistent *persist = pci_get_drvdata(pdev);
+	struct mlx4_dev	 *dev  = persist->dev;
+	struct mlx4_priv *priv = mlx4_priv(dev);
+	int nvfs[MLX4_MAX_PORTS + 1] = {0, 0, 0};
+	int total_vfs;
+	int err;
 
+	mlx4_err(dev, "%s was called\n", __func__);
 	total_vfs = dev->persist->num_vfs;
 	memcpy(nvfs, dev->persist->nvfs, sizeof(dev->persist->nvfs));
 
 	mutex_lock(&persist->interface_state_mutex);
 	if (!(persist->interface_state & MLX4_INTERFACE_STATE_UP)) {
-		ret = mlx4_load_one(pdev, priv->pci_dev_data, total_vfs, nvfs,
+		err = mlx4_load_one(pdev, priv->pci_dev_data, total_vfs, nvfs,
 				    priv, 1);
-		if (ret) {
-			mlx4_err(dev, "%s: mlx4_load_one failed, ret=%d\n",
-				 __func__,  ret);
+		if (err) {
+			mlx4_err(dev, "%s: mlx4_load_one failed, err=%d\n",
+				 __func__,  err);
 			goto end;
 		}
 
-		ret = restore_current_port_types(dev, dev->persist->
+		err = restore_current_port_types(dev, dev->persist->
 						 curr_port_type, dev->persist->
 						 curr_port_poss_type);
-		if (ret)
-			mlx4_err(dev, "could not restore original port types (%d)\n", ret);
+		if (err)
+			mlx4_err(dev, "could not restore original port types (%d)\n", err);
 	}
 end:
 	mutex_unlock(&persist->interface_state_mutex);
 
-	return ret ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
 }
 
 static void mlx4_shutdown(struct pci_dev *pdev)
@@ -3934,6 +3942,7 @@ static void mlx4_shutdown(struct pci_dev *pdev)
 static const struct pci_error_handlers mlx4_err_handler = {
 	.error_detected = mlx4_pci_err_detected,
 	.slot_reset     = mlx4_pci_slot_reset,
+	.resume		= mlx4_pci_resume,
 };
 
 static struct pci_driver mlx4_driver = {