e1000e: only perform ESB2 MDIC workaround on certain configurations

A workaround added for all ESB2 devices (adds a delay for all MDIC accesses
which resolves an issue with the MDIC ready bit being set prematurely) is
applicable only to devices in which the MAC-PHY interconnect is not
operating in a certain mode with in-band MDIO.  Check the control register
for the operating mode and enable the workaround accordingly.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000e/es2lan.c

@@ -46,6 +46,9 @@
 #define E1000_KMRNCTRLSTA_HD_CTRL_1000_DEFAULT	 0x0000
 #define E1000_KMRNCTRLSTA_OPMODE_E_IDLE		 0x2000
 
+#define E1000_KMRNCTRLSTA_OPMODE_MASK		 0x000C
+#define E1000_KMRNCTRLSTA_OPMODE_INBAND_MDIO	 0x0004
+
 #define E1000_TCTL_EXT_GCEX_MASK 0x000FFC00 /* Gigabit Carry Extend Padding */
 #define DEFAULT_TCTL_EXT_GCEX_80003ES2LAN	 0x00010000
 
@@ -462,6 +465,7 @@ static s32 e1000_read_phy_reg_gg82563_80003es2lan(struct e1000_hw *hw,
 		return ret_val;
 	}
 
+	if (hw->dev_spec.e80003es2lan.mdic_wa_enable == true) {
 		/*
 		 * The "ready" bit in the MDIC register may be incorrectly set
 		 * before the device has completed the "Page Select" MDI
@@ -480,10 +484,17 @@ static s32 e1000_read_phy_reg_gg82563_80003es2lan(struct e1000_hw *hw,
 
 		udelay(200);
 
-	ret_val = e1000e_read_phy_reg_mdic(hw, MAX_PHY_REG_ADDRESS & offset,
+		ret_val = e1000e_read_phy_reg_mdic(hw,
+		                                  MAX_PHY_REG_ADDRESS & offset,
 		                                  data);
 
 		udelay(200);
+	} else {
+		ret_val = e1000e_read_phy_reg_mdic(hw,
+		                                  MAX_PHY_REG_ADDRESS & offset,
+		                                  data);
+	}
+
 	e1000_release_phy_80003es2lan(hw);
 
 	return ret_val;
@@ -526,7 +537,7 @@ static s32 e1000_write_phy_reg_gg82563_80003es2lan(struct e1000_hw *hw,
 		return ret_val;
 	}
 
-
+	if (hw->dev_spec.e80003es2lan.mdic_wa_enable == true) {
 		/*
 		 * The "ready" bit in the MDIC register may be incorrectly set
 		 * before the device has completed the "Page Select" MDI
@@ -544,10 +555,17 @@ static s32 e1000_write_phy_reg_gg82563_80003es2lan(struct e1000_hw *hw,
 
 		udelay(200);
 
-	ret_val = e1000e_write_phy_reg_mdic(hw, MAX_PHY_REG_ADDRESS & offset,
+		ret_val = e1000e_write_phy_reg_mdic(hw,
+		                                  MAX_PHY_REG_ADDRESS & offset,
 		                                  data);
 
 		udelay(200);
+	} else {
+		ret_val = e1000e_write_phy_reg_mdic(hw,
+		                                  MAX_PHY_REG_ADDRESS & offset,
+		                                  data);
+	}
+
 	e1000_release_phy_80003es2lan(hw);
 
 	return ret_val;
@@ -866,6 +884,19 @@ static s32 e1000_init_hw_80003es2lan(struct e1000_hw *hw)
 	reg_data &= ~0x00100000;
 	E1000_WRITE_REG_ARRAY(hw, E1000_FFLT, 0x0001, reg_data);
 
+	/* default to true to enable the MDIC W/A */
+	hw->dev_spec.e80003es2lan.mdic_wa_enable = true;
+
+	ret_val = e1000_read_kmrn_reg_80003es2lan(hw,
+	                              E1000_KMRNCTRLSTA_OFFSET >>
+	                              E1000_KMRNCTRLSTA_OFFSET_SHIFT,
+	                              &i);
+	if (!ret_val) {
+		if ((i & E1000_KMRNCTRLSTA_OPMODE_MASK) ==
+		     E1000_KMRNCTRLSTA_OPMODE_INBAND_MDIO)
+			hw->dev_spec.e80003es2lan.mdic_wa_enable = false;
+	}
+
 	/*
 	 * Clear all of the statistics registers (clear on read).  It is
 	 * important that we do this after we have tried to establish link

drivers/net/e1000e/hw.h

@@ -900,6 +900,10 @@ struct e1000_dev_spec_82571 {
 	u32 smb_counter;
 };
 
+struct e1000_dev_spec_80003es2lan {
+	bool  mdic_wa_enable;
+};
+
 struct e1000_shadow_ram {
 	u16  value;
 	bool modified;
@@ -928,6 +932,7 @@ struct e1000_hw {
 
 	union {
 		struct e1000_dev_spec_82571	e82571;
+		struct e1000_dev_spec_80003es2lan e80003es2lan;
 		struct e1000_dev_spec_ich8lan	ich8lan;
 	} dev_spec;
 };