e1000e Refactor of Runtime Power Management

Fix issues with:
RuntimePM causing the device to repeatedly flip between suspend and resume
with the interface administratively downed.
Having RuntimePM enabled interfering with the functionality of Energy
Efficient Ethernet.

Added checks to disallow functions that should not be executed if the
device is currently runtime suspended

Make runtime_idle callback to use same deterministic behavior as the igb
driver.

Signed-off-by: Dave Ertman <[e-mail]>
Acked-by: Bruce Allan <[e-mail]>
Tested-by: Jeff Pieper <[e-mail]>
Signed-off-by: Jeff Kirsher <[e-mail]>

drivers/net/ethernet/intel/e1000e/e1000.h

···
 	struct work_struct update_phy_task;
 	struct work_struct print_hang_task;
 
-	bool idle_check;
 	int phy_hang_count;
 
 	u16 tx_ring_count;

drivers/net/ethernet/intel/e1000e/netdev.c

···
 	struct e1000_hw *hw = &adapter->hw;
 	u32 rctl;
 
+	if (pm_runtime_suspended(netdev->dev.parent))
+		return;
+
 	/* Check for Promiscuous and All Multicast modes */
 	rctl = er32(RCTL);
 
···
 	adapter->tx_hang_recheck = false;
 	netif_start_queue(netdev);
 
-	adapter->idle_check = true;
 	hw->mac.get_link_status = true;
 	pm_runtime_put(&pdev->dev);
 
···
 	if (!test_bit(__E1000_DOWN, &adapter->state)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
+
+		/* Link status message must follow this format */
+		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
 	}
 
 	napi_disable(&adapter->napi);
···
 	adapter->max_frame_size = max_frame;
 	e_info("changing MTU from %d to %d\n", netdev->mtu, new_mtu);
 	netdev->mtu = new_mtu;
+
+	pm_runtime_get_sync(netdev->dev.parent);
+
 	if (netif_running(netdev))
 		e1000e_down(adapter, true);
 
···
 		e1000e_up(adapter);
 	else
 		e1000e_reset(adapter);
+
+	pm_runtime_put_sync(netdev->dev.parent);
 
 	clear_bit(__E1000_RESETTING, &adapter->state);
 
···
 			ew32(CTRL_EXT, ctrl_ext);
 		}
 
+		if (!runtime)
+			e1000e_power_up_phy(adapter);
+
 		if (adapter->flags & FLAG_IS_ICH)
 			e1000_suspend_workarounds_ich8lan(&adapter->hw);
 
···
 }
 
 #ifdef CONFIG_PM
-static bool e1000e_pm_ready(struct e1000_adapter *adapter)
-{
-	return !!adapter->tx_ring->buffer_info;
-}
-
 static int __e1000_resume(struct pci_dev *pdev)
 {
 	struct net_device *netdev = pci_get_drvdata(pdev);
···
 	e1000e_reset(adapter);
 
 	e1000_init_manageability_pt(adapter);
-
-	if (netif_running(netdev))
-		e1000e_up(adapter);
-
-	netif_device_attach(netdev);
 
 	/* If the controller has AMT, do not set DRV_LOAD until the interface
 	 * is up.  For all other cases, let the f/w know that the h/w is now
···
 #endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_RUNTIME
-static int e1000_runtime_suspend(struct device *dev)
+static int e1000e_pm_runtime_idle(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
-	if (!e1000e_pm_ready(adapter))
-		return 0;
-
-	return __e1000_shutdown(pdev, true);
-}
-
-static int e1000_idle(struct device *dev)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct net_device *netdev = pci_get_drvdata(pdev);
-	struct e1000_adapter *adapter = netdev_priv(netdev);
-
-	if (!e1000e_pm_ready(adapter))
-		return 0;
-
-	if (adapter->idle_check) {
-		adapter->idle_check = false;
-		if (!e1000e_has_link(adapter))
-			pm_schedule_suspend(dev, MSEC_PER_SEC);
-	}
+	if (!e1000e_has_link(adapter))
+		pm_schedule_suspend(dev, 5 * MSEC_PER_SEC);
 
 	return -EBUSY;
 }
 
-static int e1000_runtime_resume(struct device *dev)
+static int e1000e_pm_runtime_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct net_device *netdev = pci_get_drvdata(pdev);
+	struct e1000_adapter *adapter = netdev_priv(netdev);
+	int rc;
+
+	rc = __e1000_resume(pdev);
+	if (rc)
+		return rc;
+
+	if (netdev->flags & IFF_UP)
+		rc = e1000e_up(adapter);
+
+	return rc;
+}
+
+static int e1000e_pm_runtime_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
-	if (!e1000e_pm_ready(adapter))
-		return 0;
+	if (netdev->flags & IFF_UP) {
+		int count = E1000_CHECK_RESET_COUNT;
 
-	adapter->idle_check = !dev->power.runtime_auto;
-	return __e1000_resume(pdev);
+		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
+			usleep_range(10000, 20000);
+
+		WARN_ON(test_bit(__E1000_RESETTING, &adapter->state));
+
+		/* Down the device without resetting the hardware */
+		e1000e_down(adapter, false);
+	}
+
+	if (__e1000_shutdown(pdev, true)) {
+		e1000e_pm_runtime_resume(dev);
+		return -EBUSY;
+	}
+
+	return 0;
 }
 #endif /* CONFIG_PM_RUNTIME */
 #endif /* CONFIG_PM */
···
 	.thaw		= e1000e_pm_thaw,
 	.poweroff	= e1000e_pm_suspend,
 	.restore	= e1000e_pm_resume,
-	SET_RUNTIME_PM_OPS(e1000_runtime_suspend, e1000_runtime_resume,
-			   e1000_idle)
+	SET_RUNTIME_PM_OPS(e1000e_pm_runtime_suspend, e1000e_pm_runtime_resume,
+			   e1000e_pm_runtime_idle)
 };
 
 /* PCI Device API Driver */