e1000e: clear PHY wakeup bit after LCD reset on 82577/82578

Performing a dummy read of the PHY Wakeup Control (WUC) register clears the
wakeup enable bit set by an PHY reset.  If this bit remains set, link
problems may occur.

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, 9 insertions, 1 deletions

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index aa0ab0eb8c7d..ead66510e22f 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -844,7 +844,7 @@ static s32 e1000_phy_hw_reset_ich8lan(struct e1000_hw *hw)
         u32 i;
         u32 data, cnf_size, cnf_base_addr, sw_cfg_mask;
         s32 ret_val;
-        u16 word_addr, reg_data, reg_addr, phy_page = 0;
+        u16 reg, word_addr, reg_data, reg_addr, phy_page = 0;
 
         ret_val = e1000e_phy_hw_reset_generic(hw);
         if (ret_val)
@@ -859,6 +859,10 @@ static s32 e1000_phy_hw_reset_ich8lan(struct e1000_hw *hw)
                         return ret_val;
         }
 
+        /* Dummy read to clear the phy wakeup bit after lcd reset */
+        if (hw->mac.type == e1000_pchlan)
+                e1e_rphy(hw, BM_WUC, &reg);
+
         /*
          * Initialize the PHY from the NVM on ICH platforms.  This
          * is needed due to an issue where the NVM configuration is
@@ -2229,6 +2233,7 @@ static s32 e1000_get_bus_info_ich8lan(struct e1000_hw *hw)
  **/
 static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
 {
+        u16 reg;
         u32 ctrl, icr, kab;
         s32 ret_val;
 
@@ -2304,6 +2309,9 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
                         hw_dbg(hw, "Auto Read Done did not complete\n");
                 }
         }
+        /* Dummy read to clear the phy wakeup bit after lcd reset */
+        if (hw->mac.type == e1000_pchlan)
+                e1e_rphy(hw, BM_WUC, &reg);
 
         /*
          * For PCH, this write will make sure that any noise