e1000e: disable K1 at 1000Mbps for 82577/82578

This workaround is required for an issue in hardware where noise on the
interconnect between the MAC and PHY could be generated by a lower power
mode (K1) at 1000Mbps resulting in bad packets.  Disable K1 while at 1000
Mbps but keep it enabled for 10/100Mbps and when the cable is disconnected.

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, 106 insertions, 1 deletions

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 0e0755f0db3f..d56c7473144a 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -461,6 +461,95 @@ static s32 e1000_init_mac_params_ich8lan(struct e1000_adapter *adapter)
         return 0;
 }
 
+/**
+ *  e1000_check_for_copper_link_ich8lan - Check for link (Copper)
+ *  @hw: pointer to the HW structure
+ *
+ *  Checks to see of the link status of the hardware has changed.  If a
+ *  change in link status has been detected, then we read the PHY registers
+ *  to get the current speed/duplex if link exists.
+ **/
+static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
+{
+        struct e1000_mac_info *mac = &hw->mac;
+        s32 ret_val;
+        bool link;
+
+        /*
+         * We only want to go out to the PHY registers to see if Auto-Neg
+         * has completed and/or if our link status has changed.  The
+         * get_link_status flag is set upon receiving a Link Status
+         * Change or Rx Sequence Error interrupt.
+         */
+        if (!mac->get_link_status) {
+                ret_val = 0;
+                goto out;
+        }
+
+        if (hw->mac.type == e1000_pchlan) {
+                ret_val = e1000e_write_kmrn_reg(hw,
+                                                   E1000_KMRNCTRLSTA_K1_CONFIG,
+                                                   E1000_KMRNCTRLSTA_K1_ENABLE);
+                if (ret_val)
+                        goto out;
+        }
+
+        /*
+         * First we want to see if the MII Status Register reports
+         * link.  If so, then we want to get the current speed/duplex
+         * of the PHY.
+         */
+        ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
+        if (ret_val)
+                goto out;
+
+        if (!link)
+                goto out; /* No link detected */
+
+        mac->get_link_status = false;
+
+        if (hw->phy.type == e1000_phy_82578) {
+                ret_val = e1000_link_stall_workaround_hv(hw);
+                if (ret_val)
+                        goto out;
+        }
+
+        /*
+         * Check if there was DownShift, must be checked
+         * immediately after link-up
+         */
+        e1000e_check_downshift(hw);
+
+        /*
+         * If we are forcing speed/duplex, then we simply return since
+         * we have already determined whether we have link or not.
+         */
+        if (!mac->autoneg) {
+                ret_val = -E1000_ERR_CONFIG;
+                goto out;
+        }
+
+        /*
+         * Auto-Neg is enabled.  Auto Speed Detection takes care
+         * of MAC speed/duplex configuration.  So we only need to
+         * configure Collision Distance in the MAC.
+         */
+        e1000e_config_collision_dist(hw);
+
+        /*
+         * Configure Flow Control now that Auto-Neg has completed.
+         * First, we need to restore the desired flow control
+         * settings because we may have had to re-autoneg with a
+         * different link partner.
+         */
+        ret_val = e1000e_config_fc_after_link_up(hw);
+        if (ret_val)
+                hw_dbg(hw, "Error configuring flow control\n");
+
+out:
+        return ret_val;
+}
+
 static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)
 {
         struct e1000_hw *hw = &adapter->hw;
@@ -2224,6 +2313,14 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
                 }
         }
 
+        /*
+         * For PCH, this write will make sure that any noise
+         * will be detected as a CRC error and be dropped rather than show up
+         * as a bad packet to the DMA engine.
+         */
+        if (hw->mac.type == e1000_pchlan)
+                ew32(CRC_OFFSET, 0x65656565);
+
         ew32(IMC, 0xffffffff);
         icr = er32(ICR);
 
@@ -2538,6 +2635,14 @@ static s32 e1000_get_link_up_info_ich8lan(struct e1000_hw *hw, u16 *speed,
         if (ret_val)
                 return ret_val;
 
+        if ((hw->mac.type == e1000_pchlan) && (*speed == SPEED_1000)) {
+                ret_val = e1000e_write_kmrn_reg(hw,
+                                                  E1000_KMRNCTRLSTA_K1_CONFIG,
+                                                  E1000_KMRNCTRLSTA_K1_DISABLE);
+                if (ret_val)
+                        return ret_val;
+        }
+
         if ((hw->mac.type == e1000_ich8lan) &&
             (hw->phy.type == e1000_phy_igp_3) &&
             (*speed == SPEED_1000)) {
@@ -2984,7 +3089,7 @@ static void e1000_clear_hw_cntrs_ich8lan(struct e1000_hw *hw)
 static struct e1000_mac_operations ich8_mac_ops = {
         .id_led_init            = e1000e_id_led_init,
         .check_mng_mode         = e1000_check_mng_mode_ich8lan,
-        .check_for_link         = e1000e_check_for_copper_link,
+        .check_for_link         = e1000_check_for_copper_link_ich8lan,
         /* cleanup_led dependent on mac type */
         .clear_hw_cntrs         = e1000_clear_hw_cntrs_ich8lan,
         .get_bus_info           = e1000_get_bus_info_ich8lan,