e1000e: fix enabling of EEE on 82579 and I217

Energy Efficient Ethernet on 82579 and I217 should only be enabled if not
disabled by the user, if the link is full duplex and the link partner has
similar EEE capabilities (stored in different EMI registers on the two
different parts).

After enabling EEE, read the IEEE MMD register 3.1 (which is also stored in
different EMI registers on the two different parts) to clear the count of
received Tx/Rx LPI indications.

Also, rename I217_EEE_100_SUPPORTED to I82579_EEE_100_SUPPORTED to indicate
the bit is valid starting with I82579 (released before I217).

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/ich8lan.c

@@ -150,6 +150,8 @@
 
 /* PHY Low Power Idle Control */
 #define I82579_LPI_CTRL				PHY_REG(772, 20)
+#define I82579_LPI_CTRL_100_ENABLE		0x2000
+#define I82579_LPI_CTRL_1000_ENABLE		0x4000
 #define I82579_LPI_CTRL_ENABLE_MASK		0x6000
 #define I82579_LPI_CTRL_FORCE_PLL_LOCK_COUNT	0x80
 
@@ -160,9 +162,13 @@
 #define I82579_MSE_THRESHOLD    0x084F	/* 82579 Mean Square Error Threshold */
 #define I82577_MSE_THRESHOLD    0x0887	/* 82577 Mean Square Error Threshold */
 #define I82579_MSE_LINK_DOWN    0x2411	/* MSE count before dropping link */
+#define I82579_EEE_PCS_STATUS	0x182D	/* IEEE MMD Register 3.1 >> 8 */
+#define I82579_EEE_LP_ABILITY	0x040F	/* IEEE MMD Register 7.61 */
+#define I82579_EEE_100_SUPPORTED	(1 << 1) /* 100BaseTx EEE supported */
+#define I82579_EEE_1000_SUPPORTED	(1 << 2) /* 1000BaseTx EEE supported */
+#define I217_EEE_PCS_STATUS	0x9401	/* IEEE MMD Register 3.1 */
 #define I217_EEE_ADVERTISEMENT  0x8001	/* IEEE MMD Register 7.60 */
 #define I217_EEE_LP_ABILITY     0x8002	/* IEEE MMD Register 7.61 */
-#define I217_EEE_100_SUPPORTED  (1 << 1)	/* 100BaseTx EEE supported */
 
 /* Intel Rapid Start Technology Support */
 #define I217_PROXY_CTRL                 BM_PHY_REG(BM_WUC_PAGE, 70)
@@ -845,54 +851,84 @@ static s32 e1000_write_emi_reg_locked(struct e1000_hw *hw, u16 addr, u16 data)
  *  e1000_set_eee_pchlan - Enable/disable EEE support
  *  @hw: pointer to the HW structure
  *
- *  Enable/disable EEE based on setting in dev_spec structure.  The bits in
- *  the LPI Control register will remain set only if/when link is up.
+ *  Enable/disable EEE based on setting in dev_spec structure, the duplex of
+ *  the link and the EEE capabilities of the link partner.  The LPI Control
+ *  register bits will remain set only if/when link is up.
  **/
 static s32 e1000_set_eee_pchlan(struct e1000_hw *hw)
 {
 	struct e1000_dev_spec_ich8lan *dev_spec = &hw->dev_spec.ich8lan;
-	s32 ret_val = 0;
-	u16 phy_reg;
+	s32 ret_val;
+	u16 lpi_ctrl;
 
 	if ((hw->phy.type != e1000_phy_82579) &&
 	    (hw->phy.type != e1000_phy_i217))
 		return 0;
 
-	ret_val = e1e_rphy(hw, I82579_LPI_CTRL, &phy_reg);
+	ret_val = hw->phy.ops.acquire(hw);
 	if (ret_val)
 		return ret_val;
 
-	if (dev_spec->eee_disable)
-		phy_reg &= ~I82579_LPI_CTRL_ENABLE_MASK;
-	else
-		phy_reg |= I82579_LPI_CTRL_ENABLE_MASK;
-
-	ret_val = e1e_wphy(hw, I82579_LPI_CTRL, phy_reg);
+	ret_val = e1e_rphy_locked(hw, I82579_LPI_CTRL, &lpi_ctrl);
 	if (ret_val)
-		return ret_val;
+		goto release;
+
+	/* Clear bits that enable EEE in various speeds */
+	lpi_ctrl &= ~I82579_LPI_CTRL_ENABLE_MASK;
+
+	/* Enable EEE if not disabled by user */
+	if (!dev_spec->eee_disable) {
+		u16 lpa, pcs_status, data;
 
-	if ((hw->phy.type == e1000_phy_i217) && !dev_spec->eee_disable) {
 		/* Save off link partner's EEE ability */
-		ret_val = hw->phy.ops.acquire(hw);
-		if (ret_val)
-			return ret_val;
-		ret_val = e1000_read_emi_reg_locked(hw,
-						    I217_EEE_LP_ABILITY,
+		switch (hw->phy.type) {
+		case e1000_phy_82579:
+			lpa = I82579_EEE_LP_ABILITY;
+			pcs_status = I82579_EEE_PCS_STATUS;
+			break;
+		case e1000_phy_i217:
+			lpa = I217_EEE_LP_ABILITY;
+			pcs_status = I217_EEE_PCS_STATUS;
+			break;
+		default:
+			ret_val = -E1000_ERR_PHY;
+			goto release;
+		}
+		ret_val = e1000_read_emi_reg_locked(hw, lpa,
 						    &dev_spec->eee_lp_ability);
 		if (ret_val)
 			goto release;
 
-		/* EEE is not supported in 100Half, so ignore partner's EEE
-		 * in 100 ability if full-duplex is not advertised.
+		/* Enable EEE only for speeds in which the link partner is
+		 * EEE capable.
 		 */
-		e1e_rphy_locked(hw, PHY_LP_ABILITY, &phy_reg);
-		if (!(phy_reg & NWAY_LPAR_100TX_FD_CAPS))
-			dev_spec->eee_lp_ability &= ~I217_EEE_100_SUPPORTED;
-release:
-		hw->phy.ops.release(hw);
+		if (dev_spec->eee_lp_ability & I82579_EEE_1000_SUPPORTED)
+			lpi_ctrl |= I82579_LPI_CTRL_1000_ENABLE;
+
+		if (dev_spec->eee_lp_ability & I82579_EEE_100_SUPPORTED) {
+			e1e_rphy_locked(hw, PHY_LP_ABILITY, &data);
+			if (data & NWAY_LPAR_100TX_FD_CAPS)
+				lpi_ctrl |= I82579_LPI_CTRL_100_ENABLE;
+			else
+				/* EEE is not supported in 100Half, so ignore
+				 * partner's EEE in 100 ability if full-duplex
+				 * is not advertised.
+				 */
+				dev_spec->eee_lp_ability &=
+				    ~I82579_EEE_100_SUPPORTED;
+		}
+
+		/* R/Clr IEEE MMD 3.1 bits 11:10 - Tx/Rx LPI Received */
+		ret_val = e1000_read_emi_reg_locked(hw, pcs_status, &data);
+		if (ret_val)
+			goto release;
 	}
 
-	return 0;
+	ret_val = e1e_wphy_locked(hw, I82579_LPI_CTRL, lpi_ctrl);
+release:
+	hw->phy.ops.release(hw);
+
+	return ret_val;
 }
 
 /**
@@ -4075,9 +4111,9 @@ void e1000_suspend_workarounds_ich8lan(struct e1000_hw *hw)
 			 * EEE and 100Full is advertised on both ends of the
 			 * link.
 			 */
-			if ((eee_advert & I217_EEE_100_SUPPORTED) &&
+			if ((eee_advert & I82579_EEE_100_SUPPORTED) &&
 			    (dev_spec->eee_lp_ability &
-			     I217_EEE_100_SUPPORTED) &&
+			     I82579_EEE_100_SUPPORTED) &&
 			    (hw->phy.autoneg_advertised & ADVERTISE_100_FULL))
 				phy_ctrl &= ~(E1000_PHY_CTRL_D0A_LPLU |
 					      E1000_PHY_CTRL_NOND0A_LPLU);