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: 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>

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 0bfef8e16a7bf859587ea59c98662791d7bd47c0..b8c4dce01a04ece9a4205d4f011823660bf65008 100644 (file)
--- a/drivers/net/e1000e/ich8lan.c
+++ b/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)