drivers/net/ethernet/e1000e: check return value of e1e_rphy()

e1e_rphy() could return error value when reading PHY register, which
needs to be checked.
Signed-off-by: Li Zhong <floridsleeves@gmail.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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

@@ -2697,9 +2697,14 @@ static s32 e1000_access_phy_wakeup_reg_bm(struct e1000_hw *hw, u32 offset,
 void e1000_power_up_phy_copper(struct e1000_hw *hw)
 {
 	u16 mii_reg = 0;
+	int ret;
 
 	/* The PHY will retain its settings across a power down/up cycle */
-	e1e_rphy(hw, MII_BMCR, &mii_reg);
+	ret = e1e_rphy(hw, MII_BMCR, &mii_reg);
+	if (ret) {
+		e_dbg("Error reading PHY register\n");
+		return;
+	}
 	mii_reg &= ~BMCR_PDOWN;
 	e1e_wphy(hw, MII_BMCR, mii_reg);
 }
@@ -2715,9 +2720,14 @@ void e1000_power_up_phy_copper(struct e1000_hw *hw)
 void e1000_power_down_phy_copper(struct e1000_hw *hw)
 {
 	u16 mii_reg = 0;
+	int ret;
 
 	/* The PHY will retain its settings across a power down/up cycle */
-	e1e_rphy(hw, MII_BMCR, &mii_reg);
+	ret = e1e_rphy(hw, MII_BMCR, &mii_reg);
+	if (ret) {
+		e_dbg("Error reading PHY register\n");
+		return;
+	}
 	mii_reg |= BMCR_PDOWN;
 	e1e_wphy(hw, MII_BMCR, mii_reg);
 	usleep_range(1000, 2000);
@@ -3037,7 +3047,11 @@ s32 e1000_link_stall_workaround_hv(struct e1000_hw *hw)
 		return 0;
 
 	/* Do not apply workaround if in PHY loopback bit 14 set */
-	e1e_rphy(hw, MII_BMCR, &data);
+	ret_val = e1e_rphy(hw, MII_BMCR, &data);
+	if (ret_val) {
+		e_dbg("Error reading PHY register\n");
+		return ret_val;
+	}
 	if (data & BMCR_LOOPBACK)
 		return 0;