5 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/e1000e/82571.c b/drivers/net/e1000e/82571.c
index b979464091bb..02d67d047d96 100644
--- a/drivers/net/e1000e/82571.c
+++ b/drivers/net/e1000e/82571.c
@@ -237,6 +237,8 @@ static s32 e1000_init_mac_params_82571(struct e1000_adapter *adapter)
         /* Set if manageability features are enabled. */
         mac->arc_subsystem_valid = (er32(FWSM) & E1000_FWSM_MODE_MASK)
                         ? true : false;
+        /* Adaptive IFS supported */
+        mac->adaptive_ifs = true;
 
         /* check for link */
         switch (hw->phy.media_type) {
diff --git a/drivers/net/e1000e/es2lan.c b/drivers/net/e1000e/es2lan.c
index 3028f23da891..e2aa3b788564 100644
--- a/drivers/net/e1000e/es2lan.c
+++ b/drivers/net/e1000e/es2lan.c
@@ -224,6 +224,8 @@ static s32 e1000_init_mac_params_80003es2lan(struct e1000_adapter *adapter)
         /* Set if manageability features are enabled. */
         mac->arc_subsystem_valid = (er32(FWSM) & E1000_FWSM_MODE_MASK)
                         ? true : false;
+        /* Adaptive IFS not supported */
+        mac->adaptive_ifs = false;
 
         /* check for link */
         switch (hw->phy.media_type) {
diff --git a/drivers/net/e1000e/hw.h b/drivers/net/e1000e/hw.h
index 2784cf44a6f3..eccf29b75c41 100644
--- a/drivers/net/e1000e/hw.h
+++ b/drivers/net/e1000e/hw.h
@@ -818,6 +818,7 @@ struct e1000_mac_info {
 
         u8  forced_speed_duplex;
 
+        bool adaptive_ifs;
         bool arc_subsystem_valid;
         bool autoneg;
         bool autoneg_failed;
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 9b09246af064..ad08cf3f40c0 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -454,6 +454,8 @@ static s32 e1000_init_mac_params_ich8lan(struct e1000_adapter *adapter)
                 mac->rar_entry_count--;
         /* Set if manageability features are enabled. */
         mac->arc_subsystem_valid = true;
+        /* Adaptive IFS supported */
+        mac->adaptive_ifs = true;
 
         /* LED operations */
         switch (mac->type) {
diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index a86c17548c1e..56b59e4a6871 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -1609,6 +1609,11 @@ void e1000e_reset_adaptive(struct e1000_hw *hw)
 {
         struct e1000_mac_info *mac = &hw->mac;
 
+        if (!mac->adaptive_ifs) {
+                e_dbg("Not in Adaptive IFS mode!\n");
+                goto out;
+        }
+
         mac->current_ifs_val = 0;
         mac->ifs_min_val = IFS_MIN;
         mac->ifs_max_val = IFS_MAX;
@@ -1617,6 +1622,8 @@ void e1000e_reset_adaptive(struct e1000_hw *hw)
 
         mac->in_ifs_mode = false;
         ew32(AIT, 0);
+out:
+        return;
 }
 
 /**
@@ -1630,6 +1637,11 @@ void e1000e_update_adaptive(struct e1000_hw *hw)
 {
         struct e1000_mac_info *mac = &hw->mac;
 
+        if (!mac->adaptive_ifs) {
+                e_dbg("Not in Adaptive IFS mode!\n");
+                goto out;
+        }
+
         if ((mac->collision_delta * mac->ifs_ratio) > mac->tx_packet_delta) {
                 if (mac->tx_packet_delta > MIN_NUM_XMITS) {
                         mac->in_ifs_mode = true;
@@ -1650,6 +1662,8 @@ void e1000e_update_adaptive(struct e1000_hw *hw)
                         ew32(AIT, 0);
                 }
         }
+out:
+        return;
 }
 
 /**