[PATCH 1/2] r8169 / PCI / PM: Add simplified runtime PM support (rev. 3)

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rjw@sisk.pl>

Use the PCI runtime power management framework to add basic PCI
runtime PM support to the r8169 driver.  Namely, make the driver
suspend the device when the link is not present and set it up for
generating a wakeup event after the link has been detected again.
[This feature is disabled until the user space enables it with the
help of the /sys/devices/.../power/contol device attribute.]

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/net/r8169.c |  152 ++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 125 insertions(+), 27 deletions(-)

Index: linux-2.6/drivers/net/r8169.c
===================================================================
--- linux-2.6.orig/drivers/net/r8169.c
+++ linux-2.6/drivers/net/r8169.c
@@ -23,6 +23,7 @@
 #include <linux/tcp.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
+#include <linux/pm_runtime.h>
 
 #include <asm/system.h>
 #include <asm/io.h>
@@ -504,6 +505,7 @@ struct rtl8169_private {
 
 	struct mii_if_info mii;
 	struct rtl8169_counters counters;
+	u32 saved_wolopts;
 };
 
 MODULE_AUTHOR("Realtek and the Linux r8169 crew <netdev@vger.kernel.org>");
@@ -744,53 +746,61 @@ static void rtl8169_check_link_status(st
 
 	spin_lock_irqsave(&tp->lock, flags);
 	if (tp->link_ok(ioaddr)) {
+		/* This is to cancel a scheduled suspend if there's one. */
+		pm_request_resume(&tp->pci_dev->dev);
 		netif_carrier_on(dev);
 		netif_info(tp, ifup, dev, "link up\n");
 	} else {
 		netif_carrier_off(dev);
 		netif_info(tp, ifdown, dev, "link down\n");
+		pm_schedule_suspend(&tp->pci_dev->dev, 100);
 	}
 	spin_unlock_irqrestore(&tp->lock, flags);
 }
 
-static void rtl8169_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
+#define WAKE_ANY (WAKE_PHY | WAKE_MAGIC | WAKE_UCAST | WAKE_BCAST | WAKE_MCAST)
+
+static u32 __rtl8169_get_wol(struct rtl8169_private *tp)
 {
-	struct rtl8169_private *tp = netdev_priv(dev);
 	void __iomem *ioaddr = tp->mmio_addr;
 	u8 options;
-
-	wol->wolopts = 0;
-
-#define WAKE_ANY (WAKE_PHY | WAKE_MAGIC | WAKE_UCAST | WAKE_BCAST | WAKE_MCAST)
-	wol->supported = WAKE_ANY;
-
-	spin_lock_irq(&tp->lock);
+	u32 wolopts = 0;
 
 	options = RTL_R8(Config1);
 	if (!(options & PMEnable))
-		goto out_unlock;
+		return 0;
 
 	options = RTL_R8(Config3);
 	if (options & LinkUp)
-		wol->wolopts |= WAKE_PHY;
+		wolopts |= WAKE_PHY;
 	if (options & MagicPacket)
-		wol->wolopts |= WAKE_MAGIC;
+		wolopts |= WAKE_MAGIC;
 
 	options = RTL_R8(Config5);
 	if (options & UWF)
-		wol->wolopts |= WAKE_UCAST;
+		wolopts |= WAKE_UCAST;
 	if (options & BWF)
-		wol->wolopts |= WAKE_BCAST;
+		wolopts |= WAKE_BCAST;
 	if (options & MWF)
-		wol->wolopts |= WAKE_MCAST;
+		wolopts |= WAKE_MCAST;
 
-out_unlock:
-	spin_unlock_irq(&tp->lock);
+	return wolopts;
 }
 
-static int rtl8169_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
+static void rtl8169_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
+
+	spin_lock_irq(&tp->lock);
+
+	wol->supported = WAKE_ANY;
+	wol->wolopts = __rtl8169_get_wol(tp);
+
+	spin_unlock_irq(&tp->lock);
+}
+
+static void __rtl8169_set_wol(struct rtl8169_private *tp, u32 wolopts)
+{
 	void __iomem *ioaddr = tp->mmio_addr;
 	unsigned int i;
 	static const struct {
@@ -807,23 +817,29 @@ static int rtl8169_set_wol(struct net_de
 		{ WAKE_ANY,   Config5, LanWake }
 	};
 
-	spin_lock_irq(&tp->lock);
-
 	RTL_W8(Cfg9346, Cfg9346_Unlock);
 
 	for (i = 0; i < ARRAY_SIZE(cfg); i++) {
 		u8 options = RTL_R8(cfg[i].reg) & ~cfg[i].mask;
-		if (wol->wolopts & cfg[i].opt)
+		if (wolopts & cfg[i].opt)
 			options |= cfg[i].mask;
 		RTL_W8(cfg[i].reg, options);
 	}
 
 	RTL_W8(Cfg9346, Cfg9346_Lock);
+}
+
+static int rtl8169_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
+{
+	struct rtl8169_private *tp = netdev_priv(dev);
+
+	spin_lock_irq(&tp->lock);
 
 	if (wol->wolopts)
 		tp->features |= RTL_FEATURE_WOL;
 	else
 		tp->features &= ~RTL_FEATURE_WOL;
+	__rtl8169_set_wol(tp, wol->wolopts);
 	device_set_wakeup_enable(&tp->pci_dev->dev, wol->wolopts);
 
 	spin_unlock_irq(&tp->lock);
@@ -3189,6 +3205,12 @@ rtl8169_init_one(struct pci_dev *pdev, c
 
 	device_set_wakeup_enable(&pdev->dev, tp->features & RTL_FEATURE_WOL);
 
+	if (pci_dev_run_wake(pdev)) {
+		pm_runtime_set_active(&pdev->dev);
+		pm_runtime_enable(&pdev->dev);
+	}
+	pm_runtime_idle(&pdev->dev);
+
 out:
 	return rc;
 
@@ -3211,10 +3233,18 @@ static void __devexit rtl8169_remove_one
 	struct net_device *dev = pci_get_drvdata(pdev);
 	struct rtl8169_private *tp = netdev_priv(dev);
 
+	pm_runtime_get_sync(&pdev->dev);
+
 	flush_scheduled_work();
 
 	unregister_netdev(dev);
 
+	if (pci_dev_run_wake(pdev)) {
+		pm_runtime_disable(&pdev->dev);
+		pm_runtime_set_suspended(&pdev->dev);
+	}
+	pm_runtime_put_noidle(&pdev->dev);
+
 	/* restore original MAC address */
 	rtl_rar_set(tp, dev->perm_addr);
 
@@ -3237,6 +3267,7 @@ static int rtl8169_open(struct net_devic
 	struct pci_dev *pdev = tp->pci_dev;
 	int retval = -ENOMEM;
 
+	pm_runtime_get_sync(&pdev->dev);
 
 	rtl8169_set_rxbufsize(tp, dev);
 
@@ -3247,7 +3278,7 @@ static int rtl8169_open(struct net_devic
 	tp->TxDescArray = pci_alloc_consistent(pdev, R8169_TX_RING_BYTES,
 					       &tp->TxPhyAddr);
 	if (!tp->TxDescArray)
-		goto out;
+		goto err_pm_runtime_put;
 
 	tp->RxDescArray = pci_alloc_consistent(pdev, R8169_RX_RING_BYTES,
 					       &tp->RxPhyAddr);
@@ -3274,6 +3305,9 @@ static int rtl8169_open(struct net_devic
 
 	rtl8169_request_timer(dev);
 
+	tp->saved_wolopts = 0;
+	pm_runtime_put_noidle(&pdev->dev);
+
 	rtl8169_check_link_status(dev, tp, tp->mmio_addr);
 out:
 	return retval;
@@ -3283,9 +3317,13 @@ err_release_ring_2:
 err_free_rx_1:
 	pci_free_consistent(pdev, R8169_RX_RING_BYTES, tp->RxDescArray,
 			    tp->RxPhyAddr);
+	tp->RxDescArray = NULL;
 err_free_tx_0:
 	pci_free_consistent(pdev, R8169_TX_RING_BYTES, tp->TxDescArray,
 			    tp->TxPhyAddr);
+	tp->TxDescArray = NULL;
+err_pm_runtime_put:
+	pm_runtime_put_noidle(&pdev->dev);
 	goto out;
 }
 
@@ -4692,6 +4730,8 @@ static int rtl8169_close(struct net_devi
 	struct rtl8169_private *tp = netdev_priv(dev);
 	struct pci_dev *pdev = tp->pci_dev;
 
+	pm_runtime_get_sync(&pdev->dev);
+
 	/* update counters before going down */
 	rtl8169_update_counters(dev);
 
@@ -4706,6 +4746,8 @@ static int rtl8169_close(struct net_devi
 	tp->TxDescArray = NULL;
 	tp->RxDescArray = NULL;
 
+	pm_runtime_put_sync(&pdev->dev);
+
 	return 0;
 }
 
@@ -4804,21 +4846,74 @@ static int rtl8169_suspend(struct device
 	return 0;
 }
 
+static void __rtl8169_resume(struct net_device *dev)
+{
+	netif_device_attach(dev);
+	rtl8169_schedule_work(dev, rtl8169_reset_task);
+}
+
 static int rtl8169_resume(struct device *device)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct net_device *dev = pci_get_drvdata(pdev);
 
-	if (!netif_running(dev))
-		goto out;
+	if (netif_running(dev))
+		__rtl8169_resume(dev);
 
-	netif_device_attach(dev);
+	return 0;
+}
+
+static int rtl8169_runtime_suspend(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct net_device *dev = pci_get_drvdata(pdev);
+	struct rtl8169_private *tp = netdev_priv(dev);
+
+	if (!tp->TxDescArray)
+		return 0;
+
+	spin_lock_irq(&tp->lock);
+	tp->saved_wolopts = __rtl8169_get_wol(tp);
+	__rtl8169_set_wol(tp, WAKE_ANY);
+	spin_unlock_irq(&tp->lock);
+
+	rtl8169_net_suspend(dev);
+
+	return 0;
+}
+
+static int rtl8169_runtime_resume(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct net_device *dev = pci_get_drvdata(pdev);
+	struct rtl8169_private *tp = netdev_priv(dev);
+
+	if (!tp->TxDescArray)
+		return 0;
+
+	spin_lock_irq(&tp->lock);
+	__rtl8169_set_wol(tp, tp->saved_wolopts);
+	tp->saved_wolopts = 0;
+	spin_unlock_irq(&tp->lock);
+
+	__rtl8169_resume(dev);
 
-	rtl8169_schedule_work(dev, rtl8169_reset_task);
-out:
 	return 0;
 }
 
+static int rtl8169_runtime_idle(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct net_device *dev = pci_get_drvdata(pdev);
+	struct rtl8169_private *tp = netdev_priv(dev);
+
+	if (!tp->TxDescArray)
+		return 0;
+
+	rtl8169_check_link_status(dev, tp, tp->mmio_addr);
+	return -EBUSY;
+}
+
 static const struct dev_pm_ops rtl8169_pm_ops = {
 	.suspend = rtl8169_suspend,
 	.resume = rtl8169_resume,
@@ -4826,6 +4921,9 @@ static const struct dev_pm_ops rtl8169_p
 	.thaw = rtl8169_resume,
 	.poweroff = rtl8169_suspend,
 	.restore = rtl8169_resume,
+	.runtime_suspend = rtl8169_runtime_suspend,
+	.runtime_resume = rtl8169_runtime_resume,
+	.runtime_idle = rtl8169_runtime_idle,
 };
 
 #define RTL8169_PM_OPS	(&rtl8169_pm_ops)