e1000e: i219 - fix to enable both ULP and EEE in Sx state

In i219, there is a hardware bug that prevented ULP entry.
A side effect of the original software fix for this was that EEE in
Sx couldn't be enabled.
This patch implements a modified flow that allows both ULP and EEE in Sx.

Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -1089,6 +1089,7 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
 	u32 mac_reg;
 	s32 ret_val = 0;
 	u16 phy_reg;
+	u16 oem_reg = 0;
 
 	if ((hw->mac.type < e1000_pch_lpt) ||
 	    (hw->adapter->pdev->device == E1000_DEV_ID_PCH_LPT_I217_LM) ||
@@ -1130,33 +1131,37 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
 	if (ret_val)
 		goto out;
 
+	/* Force SMBus mode in PHY */
+	ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
+	if (ret_val)
+		goto release;
+	phy_reg |= CV_SMB_CTRL_FORCE_SMBUS;
+	e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);
+
+	/* Force SMBus mode in MAC */
+	mac_reg = er32(CTRL_EXT);
+	mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
+	ew32(CTRL_EXT, mac_reg);
+
 	/* Si workaround for ULP entry flow on i127/rev6 h/w.  Enable
 	 * LPLU and disable Gig speed when entering ULP
 	 */
 	if ((hw->phy.type == e1000_phy_i217) && (hw->phy.revision == 6)) {
 		ret_val = e1000_read_phy_reg_hv_locked(hw, HV_OEM_BITS,
-						       &phy_reg);
+						       &oem_reg);
 		if (ret_val)
 			goto release;
+
+		phy_reg = oem_reg;
 		phy_reg |= HV_OEM_BITS_LPLU | HV_OEM_BITS_GBE_DIS;
+
 		ret_val = e1000_write_phy_reg_hv_locked(hw, HV_OEM_BITS,
 							phy_reg);
+
 		if (ret_val)
 			goto release;
 	}
 
-	/* Force SMBus mode in PHY */
-	ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
-	if (ret_val)
-		goto release;
-	phy_reg |= CV_SMB_CTRL_FORCE_SMBUS;
-	e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);
-
-	/* Force SMBus mode in MAC */
-	mac_reg = er32(CTRL_EXT);
-	mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
-	ew32(CTRL_EXT, mac_reg);
-
 	/* Set Inband ULP Exit, Reset to SMBus mode and
 	 * Disable SMBus Release on PERST# in PHY
 	 */
@@ -1168,10 +1173,15 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
 	if (to_sx) {
 		if (er32(WUFC) & E1000_WUFC_LNKC)
 			phy_reg |= I218_ULP_CONFIG1_WOL_HOST;
+		else
+			phy_reg &= ~I218_ULP_CONFIG1_WOL_HOST;
 
 		phy_reg |= I218_ULP_CONFIG1_STICKY_ULP;
+		phy_reg &= ~I218_ULP_CONFIG1_INBAND_EXIT;
 	} else {
 		phy_reg |= I218_ULP_CONFIG1_INBAND_EXIT;
+		phy_reg &= ~I218_ULP_CONFIG1_STICKY_ULP;
+		phy_reg &= ~I218_ULP_CONFIG1_WOL_HOST;
 	}
 	e1000_write_phy_reg_hv_locked(hw, I218_ULP_CONFIG1, phy_reg);
 
@@ -1183,6 +1193,15 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
 	/* Commit ULP changes in PHY by starting auto ULP configuration */
 	phy_reg |= I218_ULP_CONFIG1_START;
 	e1000_write_phy_reg_hv_locked(hw, I218_ULP_CONFIG1, phy_reg);
+
+	if ((hw->phy.type == e1000_phy_i217) && (hw->phy.revision == 6) &&
+	    to_sx && (er32(STATUS) & E1000_STATUS_LU)) {
+		ret_val = e1000_write_phy_reg_hv_locked(hw, HV_OEM_BITS,
+							oem_reg);
+		if (ret_val)
+			goto release;
+	}
+
 release:
 	hw->phy.ops.release(hw);
 out: