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

commit 627c8a041f7aaaea93c766f69bd61d952a277586 upstream.

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>
[Backported to 2.6.32 by dann frazier <dannf@debian.org>]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index c688b55c1b7564adc002f18a5da93bf5170f9a70..de39f9a255208d963f83b2ddca16d36093369406 100644 (file)
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -274,6 +274,16 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
        phy->ops.write_phy_reg_locked = e1000_write_phy_reg_hv_locked;
        phy->autoneg_mask             = AUTONEG_ADVERTISE_SPEED_DEFAULT;
 
+       /*
+        * 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;
        e1000e_get_phy_id(hw);
        phy->type = e1000e_get_phy_type_from_id(phy->id);
@@ -287,6 +297,7 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
                phy->ops.commit_phy = e1000e_phy_sw_reset;
        }
 
+ out:
        return ret_val;
 }