e1000e: workaround link issues on busy hub in half duplex on 82577/82578

This patch removes a delay in hardware after every received packet allowing
more time for transmitted packets to go out in between received packets in
half duplex.

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, 18 insertions, 1 deletions

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index c2ea8619750..8b6ecd12788 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -1122,6 +1122,7 @@ static s32 e1000_set_mdio_slow_mode_hv(struct e1000_hw *hw)
 static s32 e1000_hv_phy_workarounds_ich8lan(struct e1000_hw *hw)
 {
         s32 ret_val = 0;
+        u16 phy_data;
 
         if (hw->mac.type != e1000_pchlan)
                 return ret_val;
@@ -1165,16 +1166,32 @@ static s32 e1000_hv_phy_workarounds_ich8lan(struct e1000_hw *hw)
 
         hw->phy.addr = 1;
         ret_val = e1000e_write_phy_reg_mdic(hw, IGP01E1000_PHY_PAGE_SELECT, 0);
+        hw->phy.ops.release(hw);
         if (ret_val)
                 goto out;
-        hw->phy.ops.release(hw);
 
         /*
          * Configure the K1 Si workaround during phy reset assuming there is
          * link so that it disables K1 if link is in 1Gbps.
          */
         ret_val = e1000_k1_gig_workaround_hv(hw, true);
+        if (ret_val)
+                goto out;
 
+        /* Workaround for link disconnects on a busy hub in half duplex */
+        ret_val = hw->phy.ops.acquire(hw);
+        if (ret_val)
+                goto out;
+        ret_val = hw->phy.ops.read_reg_locked(hw,
+                                              PHY_REG(BM_PORT_CTRL_PAGE, 17),
+                                              &phy_data);
+        if (ret_val)
+                goto release;
+        ret_val = hw->phy.ops.write_reg_locked(hw,
+                                               PHY_REG(BM_PORT_CTRL_PAGE, 17),
+                                               phy_data & 0x00FF);
+release:
+        hw->phy.ops.release(hw);
 out:
         return ret_val;
 }