e1000e: MDIO slow mode should always be done for 82577

A previous 82577 workaround that set the MDIO access speed to slow mode for
every PHY register read/write when the cable is unplugged should instead
set the access mode to always be slow before any PHY register access.
Since the mode bit gets cleared when the PHY is reset, set the mode after
every PHY reset.

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, 53 insertions, 4 deletions

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index ad08cf3f40c0..c2ea86197503 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -138,6 +138,10 @@
 #define E1000_NVM_K1_CONFIG 0x1B /* NVM K1 Config Word */
 #define E1000_NVM_K1_ENABLE 0x1  /* NVM Enable K1 bit */
 
+/* KMRN Mode Control */
+#define HV_KMRN_MODE_CTRL      PHY_REG(769, 16)
+#define HV_KMRN_MDIO_SLOW      0x0400
+
 /* ICH GbE Flash Hardware Sequencing Flash Status Register bit breakdown */
 /* Offset 04h HSFSTS */
 union ich8_hws_flash_status {
@@ -219,6 +223,7 @@ static s32 e1000_set_lplu_state_pchlan(struct e1000_hw *hw, bool active);
 static void e1000_power_down_phy_copper_ich8lan(struct e1000_hw *hw);
 static void e1000_lan_init_done_ich8lan(struct e1000_hw *hw);
 static s32  e1000_k1_gig_workaround_hv(struct e1000_hw *hw, bool link);
+static s32 e1000_set_mdio_slow_mode_hv(struct e1000_hw *hw);
 
 static inline u16 __er16flash(struct e1000_hw *hw, unsigned long reg)
 {
@@ -270,7 +275,21 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
         phy->autoneg_mask             = AUTONEG_ADVERTISE_SPEED_DEFAULT;
 
         phy->id = e1000_phy_unknown;
-        e1000e_get_phy_id(hw);
+        ret_val = e1000e_get_phy_id(hw);
+        if (ret_val)
+                goto out;
+        if ((phy->id == 0) || (phy->id == PHY_REVISION_MASK)) {
+                /*
+                 * In case the PHY needs to be in mdio slow mode (eg. 82577),
+                 * set slow mode and try to get the PHY id again.
+                 */
+                ret_val = e1000_set_mdio_slow_mode_hv(hw);
+                if (ret_val)
+                        goto out;
+                ret_val = e1000e_get_phy_id(hw);
+                if (ret_val)
+                        goto out;
+        }
         phy->type = e1000e_get_phy_type_from_id(phy->id);
 
         switch (phy->type) {
@@ -292,6 +311,7 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
                 break;
         }
 
+out:
         return ret_val;
 }
 
@@ -1076,6 +1096,26 @@ out:
 
 
 /**
+ *  e1000_set_mdio_slow_mode_hv - Set slow MDIO access mode
+ *  @hw:   pointer to the HW structure
+ **/
+static s32 e1000_set_mdio_slow_mode_hv(struct e1000_hw *hw)
+{
+        s32 ret_val;
+        u16 data;
+
+        ret_val = e1e_rphy(hw, HV_KMRN_MODE_CTRL, &data);
+        if (ret_val)
+                return ret_val;
+
+        data |= HV_KMRN_MDIO_SLOW;
+
+        ret_val = e1e_wphy(hw, HV_KMRN_MODE_CTRL, data);
+
+        return ret_val;
+}
+
+/**
  *  e1000_hv_phy_workarounds_ich8lan - A series of Phy workarounds to be
  *  done after every PHY reset.
  **/
@@ -1086,6 +1126,13 @@ static s32 e1000_hv_phy_workarounds_ich8lan(struct e1000_hw *hw)
         if (hw->mac.type != e1000_pchlan)
                 return ret_val;
 
+        /* Set MDIO slow mode before any other MDIO access */
+        if (hw->phy.type == e1000_phy_82577) {
+                ret_val = e1000_set_mdio_slow_mode_hv(hw);
+                if (ret_val)
+                        goto out;
+        }
+
         if (((hw->phy.type == e1000_phy_82577) &&
              ((hw->phy.revision == 1) || (hw->phy.revision == 2))) ||
             ((hw->phy.type == e1000_phy_82578) && (hw->phy.revision == 1))) {
@@ -1184,6 +1231,7 @@ static s32 e1000_phy_hw_reset_ich8lan(struct e1000_hw *hw)
         /* Allow time for h/w to get to a quiescent state after reset */
         mdelay(10);
 
+        /* Perform any necessary post-reset workarounds */
         if (hw->mac.type == e1000_pchlan) {
                 ret_val = e1000_hv_phy_workarounds_ich8lan(hw);
                 if (ret_val)
@@ -2484,6 +2532,10 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
         if (!ret_val)
                 e1000_release_swflag_ich8lan(hw);
 
+        /* Perform any necessary post-reset workarounds */
+        if (hw->mac.type == e1000_pchlan)
+                ret_val = e1000_hv_phy_workarounds_ich8lan(hw);
+
         if (ctrl & E1000_CTRL_PHY_RST)
                 ret_val = hw->phy.ops.get_cfg_done(hw);
 
@@ -2528,9 +2580,6 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
         kab |= E1000_KABGTXD_BGSQLBIAS;
         ew32(KABGTXD, kab);
 
-        if (hw->mac.type == e1000_pchlan)
-                ret_val = e1000_hv_phy_workarounds_ich8lan(hw);
-
 out:
         return ret_val;
 }