e1000e: fix I217/I218 PHY initialization flow

The initialization of the PHY on I217/I218, while similar to 82579, must
also check to see if the MAC and PHY are in the same mode (PCIe vs. SMBus)
otherwise the PHY will be inaccessible by the MAC.

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

@@ -185,6 +185,7 @@ static bool e1000_phy_is_accessible_pchlan(struct e1000_hw *hw)
 	u32 phy_id = 0;
 	s32 ret_val;
 	u16 retry_count;
+	u32 mac_reg = 0;
 
 	for (retry_count = 0; retry_count < 2; retry_count++) {
 		ret_val = e1e_rphy_locked(hw, MII_PHYSID1, &phy_reg);
@@ -203,11 +204,11 @@ static bool e1000_phy_is_accessible_pchlan(struct e1000_hw *hw)
 
 	if (hw->phy.id) {
 		if (hw->phy.id == phy_id)
-			return true;
+			goto out;
 	} else if (phy_id) {
 		hw->phy.id = phy_id;
 		hw->phy.revision = (u32)(phy_reg & ~PHY_REVISION_MASK);
-		return true;
+		goto out;
 	}
 
 	/* In case the PHY needs to be in mdio slow mode,
@@ -219,7 +220,22 @@ static bool e1000_phy_is_accessible_pchlan(struct e1000_hw *hw)
 		ret_val = e1000e_get_phy_id(hw);
 	hw->phy.ops.acquire(hw);
 
-	return !ret_val;
+	if (ret_val)
+		return false;
+out:
+	if (hw->mac.type == e1000_pch_lpt) {
+		/* Unforce SMBus mode in PHY */
+		e1e_rphy_locked(hw, CV_SMB_CTRL, &phy_reg);
+		phy_reg &= ~CV_SMB_CTRL_FORCE_SMBUS;
+		e1e_wphy_locked(hw, CV_SMB_CTRL, phy_reg);
+
+		/* Unforce SMBus mode in MAC */
+		mac_reg = er32(CTRL_EXT);
+		mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
+		ew32(CTRL_EXT, mac_reg);
+	}
+
+	return true;
 }
 
 /**
@@ -233,7 +249,6 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 {
 	u32 mac_reg, fwsm = er32(FWSM);
 	s32 ret_val;
-	u16 phy_reg;
 
 	/* Gate automatic PHY configuration by hardware on managed and
 	 * non-managed 82579 and newer adapters.
@@ -262,22 +277,16 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 		mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
 		ew32(CTRL_EXT, mac_reg);
 
+		/* Wait 50 milliseconds for MAC to finish any retries
+		 * that it might be trying to perform from previous
+		 * attempts to acknowledge any phy read requests.
+		 */
+		msleep(50);
+
 		/* fall-through */
 	case e1000_pch2lan:
-		if (e1000_phy_is_accessible_pchlan(hw)) {
-			if (hw->mac.type == e1000_pch_lpt) {
-				/* Unforce SMBus mode in PHY */
-				e1e_rphy_locked(hw, CV_SMB_CTRL, &phy_reg);
-				phy_reg &= ~CV_SMB_CTRL_FORCE_SMBUS;
-				e1e_wphy_locked(hw, CV_SMB_CTRL, phy_reg);
-
-				/* Unforce SMBus mode in MAC */
-				mac_reg = er32(CTRL_EXT);
-				mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
-				ew32(CTRL_EXT, mac_reg);
-			}
+		if (e1000_phy_is_accessible_pchlan(hw))
 			break;
-		}
 
 		/* fall-through */
 	case e1000_pchlan:
@@ -287,6 +296,7 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 
 		if (hw->phy.ops.check_reset_block(hw)) {
 			e_dbg("Required LANPHYPC toggle blocked by ME\n");
+			ret_val = -E1000_ERR_PHY;
 			break;
 		}
 
@@ -298,15 +308,6 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 		mac_reg |= E1000_FEXTNVM3_PHY_CFG_COUNTER_50MSEC;
 		ew32(FEXTNVM3, mac_reg);
 
-		if (hw->mac.type == e1000_pch_lpt) {
-			/* Toggling LANPHYPC brings the PHY out of SMBus mode
-			 * So ensure that the MAC is also out of SMBus mode
-			 */
-			mac_reg = er32(CTRL_EXT);
-			mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
-			ew32(CTRL_EXT, mac_reg);
-		}
-
 		/* Toggle LANPHYPC Value bit */
 		mac_reg = er32(CTRL);
 		mac_reg |= E1000_CTRL_LANPHYPC_OVERRIDE;
@@ -325,6 +326,21 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 				usleep_range(5000, 10000);
 			} while (!(er32(CTRL_EXT) &
 				   E1000_CTRL_EXT_LPCD) && count--);
+			usleep_range(30000, 60000);
+			if (e1000_phy_is_accessible_pchlan(hw))
+				break;
+
+			/* Toggling LANPHYPC brings the PHY out of SMBus mode
+			 * so ensure that the MAC is also out of SMBus mode
+			 */
+			mac_reg = er32(CTRL_EXT);
+			mac_reg &= ~E1000_CTRL_EXT_FORCE_SMBUS;
+			ew32(CTRL_EXT, mac_reg);
+
+			if (e1000_phy_is_accessible_pchlan(hw))
+				break;
+
+			ret_val = -E1000_ERR_PHY;
 		}
 		break;
 	default:
@@ -332,13 +348,14 @@ static s32 e1000_init_phy_workarounds_pchlan(struct e1000_hw *hw)
 	}
 
 	hw->phy.ops.release(hw);
-
-	/* Reset the PHY before any access to it.  Doing so, ensures
-	 * that the PHY is in a known good state before we read/write
-	 * PHY registers.  The generic reset is sufficient here,
-	 * because we haven't determined the PHY type yet.
-	 */
-	ret_val = e1000e_phy_hw_reset_generic(hw);
+	if (!ret_val) {
+		/* Reset the PHY before any access to it.  Doing so, ensures
+		 * that the PHY is in a known good state before we read/write
+		 * PHY registers.  The generic reset is sufficient here,
+		 * because we haven't determined the PHY type yet.
+		 */
+		ret_val = e1000e_phy_hw_reset_generic(hw);
+	}
 
 out:
 	/* Ungate automatic PHY configuration on non-managed 82579 */