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>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 0bfef8e16a7b..b8c4dce01a04 100644
--- 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)