e1000e: cleanup ethtool loopback setup code

Refactor the loopback setup code to first handle the only 10/100 PHY
supported by the driver if applicable and then handle the 1Gig PHYs in a
switch statement for PHY-specific setups.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000e/ethtool.c

@@ -1263,33 +1263,36 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
 
 	hw->mac.autoneg = 0;
 
-	/* Workaround: K1 must be disabled for stable 1Gbps operation */
-	if (hw->mac.type == e1000_pchlan)
-		e1000_configure_k1_ich8lan(hw, false);
-
-	if (hw->phy.type == e1000_phy_m88) {
-		/* Auto-MDI/MDIX Off */
-		e1e_wphy(hw, M88E1000_PHY_SPEC_CTRL, 0x0808);
-		/* reset to update Auto-MDI/MDIX */
-		e1e_wphy(hw, PHY_CONTROL, 0x9140);
-		/* autoneg off */
-		e1e_wphy(hw, PHY_CONTROL, 0x8140);
-	} else if (hw->phy.type == e1000_phy_gg82563)
-		e1e_wphy(hw, GG82563_PHY_KMRN_MODE_CTRL, 0x1CC);
-
-	ctrl_reg = er32(CTRL);
-
-	switch (hw->phy.type) {
-	case e1000_phy_ife:
+	if (hw->phy.type == e1000_phy_ife) {
 		/* force 100, set loopback */
 		e1e_wphy(hw, PHY_CONTROL, 0x6100);
 
 		/* Now set up the MAC to the same speed/duplex as the PHY. */
+		ctrl_reg = er32(CTRL);
 		ctrl_reg &= ~E1000_CTRL_SPD_SEL; /* Clear the speed sel bits */
 		ctrl_reg |= (E1000_CTRL_FRCSPD | /* Set the Force Speed Bit */
 			     E1000_CTRL_FRCDPX | /* Set the Force Duplex Bit */
 			     E1000_CTRL_SPD_100 |/* Force Speed to 100 */
 			     E1000_CTRL_FD);	 /* Force Duplex to FULL */
+
+		ew32(CTRL, ctrl_reg);
+		udelay(500);
+
+		return 0;
+	}
+
+	/* Specific PHY configuration for loopback */
+	switch (hw->phy.type) {
+	case e1000_phy_m88:
+		/* Auto-MDI/MDIX Off */
+		e1e_wphy(hw, M88E1000_PHY_SPEC_CTRL, 0x0808);
+		/* reset to update Auto-MDI/MDIX */
+		e1e_wphy(hw, PHY_CONTROL, 0x9140);
+		/* autoneg off */
+		e1e_wphy(hw, PHY_CONTROL, 0x8140);
+		break;
+	case e1000_phy_gg82563:
+		e1e_wphy(hw, GG82563_PHY_KMRN_MODE_CTRL, 0x1CC);
 		break;
 	case e1000_phy_bm:
 		/* Set Default MAC Interface speed to 1GB */
@@ -1312,23 +1315,30 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
 		/* Set Early Link Enable */
 		e1e_rphy(hw, PHY_REG(769, 20), &phy_reg);
 		e1e_wphy(hw, PHY_REG(769, 20), phy_reg | 0x0400);
-		/* fall through */
+		break;
+	case e1000_phy_82577:
+	case e1000_phy_82578:
+		/* Workaround: K1 must be disabled for stable 1Gbps operation */
+		e1000_configure_k1_ich8lan(hw, false);
+		break;
 	default:
-		/* force 1000, set loopback */
-		e1e_wphy(hw, PHY_CONTROL, 0x4140);
-		mdelay(250);
+		break;
+	}
 
-		/* Now set up the MAC to the same speed/duplex as the PHY. */
-		ctrl_reg = er32(CTRL);
-		ctrl_reg &= ~E1000_CTRL_SPD_SEL; /* Clear the speed sel bits */
-		ctrl_reg |= (E1000_CTRL_FRCSPD | /* Set the Force Speed Bit */
-			     E1000_CTRL_FRCDPX | /* Set the Force Duplex Bit */
-			     E1000_CTRL_SPD_1000 |/* Force Speed to 1000 */
-			     E1000_CTRL_FD);	 /* Force Duplex to FULL */
+	/* force 1000, set loopback */
+	e1e_wphy(hw, PHY_CONTROL, 0x4140);
+	mdelay(250);
 
-		if (adapter->flags & FLAG_IS_ICH)
-			ctrl_reg |= E1000_CTRL_SLU;	/* Set Link Up */
-	}
+	/* Now set up the MAC to the same speed/duplex as the PHY. */
+	ctrl_reg = er32(CTRL);
+	ctrl_reg &= ~E1000_CTRL_SPD_SEL; /* Clear the speed sel bits */
+	ctrl_reg |= (E1000_CTRL_FRCSPD | /* Set the Force Speed Bit */
+		     E1000_CTRL_FRCDPX | /* Set the Force Duplex Bit */
+		     E1000_CTRL_SPD_1000 |/* Force Speed to 1000 */
+		     E1000_CTRL_FD);	 /* Force Duplex to FULL */
+
+	if (adapter->flags & FLAG_IS_ICH)
+		ctrl_reg |= E1000_CTRL_SLU;	/* Set Link Up */
 
 	if (hw->phy.media_type == e1000_media_type_copper &&
 	    hw->phy.type == e1000_phy_m88) {