r8169: use pci_find_capability for the PCI-E features

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>

drivers/net/r8169.c

@@ -61,6 +61,7 @@ static const int multicast_filter_limit = 32;
 /* MAC address length */
 #define MAC_ADDR_LEN	6
 
+#define MAX_READ_REQUEST_SHIFT	12
 #define RX_FIFO_THRESH	7	/* 7 means NO threshold, Rx buffer level before first PCI xfer. */
 #define RX_DMA_BURST	6	/* Maximum PCI burst, '6' is 1024 */
 #define TX_DMA_BURST	6	/* Maximum PCI burst, '6' is 1024 */
@@ -412,6 +413,7 @@ struct rtl8169_private {
 	void (*hw_start)(struct net_device *);
 	unsigned int (*phy_reset_pending)(void __iomem *);
 	unsigned int (*link_ok)(void __iomem *);
+	int pcie_cap;
 	struct delayed_work task;
 	unsigned features;
 
@@ -1663,6 +1665,10 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_out_free_res_4;
 	}
 
+	tp->pcie_cap = pci_find_capability(pdev, PCI_CAP_ID_EXP);
+	if (!tp->pcie_cap && netif_msg_probe(tp))
+		dev_info(&pdev->dev, "no PCI Express capability\n");
+
 	/* Unneeded ? Don't mess with Mrs. Murphy. */
 	rtl8169_irq_mask_and_ack(ioaddr);
 
@@ -2054,13 +2060,19 @@ static void rtl_hw_start_8169(struct net_device *dev)
 	RTL_W16(IntrMask, tp->intr_event);
 }
 
-static void rtl_tx_performance_tweak(struct pci_dev *pdev, u8 force)
+static void rtl_tx_performance_tweak(struct pci_dev *pdev, u16 force)
 {
-	u8 ctl;
+	struct net_device *dev = pci_get_drvdata(pdev);
+	struct rtl8169_private *tp = netdev_priv(dev);
+	int cap = tp->pcie_cap;
+
+	if (cap) {
+		u16 ctl;
 
-	pci_read_config_byte(pdev, 0x69, &ctl);
-	ctl = (ctl & ~0x70) | force;
-	pci_write_config_byte(pdev, 0x69, ctl);
+		pci_read_config_word(pdev, cap + PCI_EXP_DEVCTL, &ctl);
+		ctl = (ctl & ~PCI_EXP_DEVCTL_READRQ) | force;
+		pci_write_config_word(pdev, cap + PCI_EXP_DEVCTL, ctl);
+	}
 }
 
 static void rtl_hw_start_8168(struct net_device *dev)
@@ -2081,7 +2093,7 @@ static void rtl_hw_start_8168(struct net_device *dev)
 
 	RTL_W16(CPlusCmd, tp->cp_cmd);
 
-	rtl_tx_performance_tweak(pdev, 0x50);
+	rtl_tx_performance_tweak(pdev, 0x5 << MAX_READ_REQUEST_SHIFT);
 
 	RTL_W16(IntrMitigate, 0x5151);
 
@@ -2116,8 +2128,12 @@ static void rtl_hw_start_8101(struct net_device *dev)
 
 	if ((tp->mac_version == RTL_GIGA_MAC_VER_13) ||
 	    (tp->mac_version == RTL_GIGA_MAC_VER_16)) {
-		pci_write_config_word(pdev, 0x68, 0x00);
-		pci_write_config_word(pdev, 0x69, 0x08);
+		int cap = tp->pcie_cap;
+
+		if (cap) {
+			pci_write_config_word(pdev, cap + PCI_EXP_DEVCTL,
+					      PCI_EXP_DEVCTL_NOSNOOP_EN);
+		}
 	}
 
 	RTL_W8(Cfg9346, Cfg9346_Unlock);