e1000e: Reset 82577/82578 PHY before first PHY register read

Reset the PHY before first accessing it.  Doing so, ensure that the PHY is
in a known good state before we read/write PHY registers. This fixes a
driver probe failure.
Signed-off-by: NBruce Allan <bruce.w.allan@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/e1000e/ich8lan.c

@@ -294,6 +294,16 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
 		msleep(50);
 	}
 
+	/*
+	 * Reset the PHY before any acccess 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)
+		goto out;
+
 	phy->id = e1000_phy_unknown;
 	ret_val = e1000e_get_phy_id(hw);
 	if (ret_val)