Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/net-queue

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2018-03-12

This series contains fixes to e1000e only.

Benjamin Poirier provides two fixes, first reverts commits that changed
what happens to the link status when there is an error.  These commits
were to resolve a race condition, but in the process of fixing the race
condition, they changed the behavior when an error occurred.  Second fix
resolves a race condition by not setting "get_link_status" to false
after checking the link.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 33 insertions, 40 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index ff308b05d68c..1dddfb7b2de6 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1367,9 +1367,6 @@ out:
  *  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.
- *
- *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- *  up).
  **/
 static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 {
@@ -1385,7 +1382,8 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * Change or Rx Sequence Error interrupt.
 	 */
 	if (!mac->get_link_status)
-		return 1;
+		return 0;
+	mac->get_link_status = false;
 
 	/* First we want to see if the MII Status Register reports
 	 * link.  If so, then we want to get the current speed/duplex
@@ -1393,12 +1391,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 */
 	ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
 	if (ret_val)
-		return ret_val;
+		goto out;
 
 	if (hw->mac.type == e1000_pchlan) {
 		ret_val = e1000_k1_gig_workaround_hv(hw, link);
 		if (ret_val)
-			return ret_val;
+			goto out;
 	}
 
 	/* When connected at 10Mbps half-duplex, some parts are excessively
@@ -1431,7 +1429,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 
 		ret_val = hw->phy.ops.acquire(hw);
 		if (ret_val)
-			return ret_val;
+			goto out;
 
 		if (hw->mac.type == e1000_pch2lan)
 			emi_addr = I82579_RX_CONFIG;
@@ -1453,7 +1451,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 		hw->phy.ops.release(hw);
 
 		if (ret_val)
-			return ret_val;
+			goto out;
 
 		if (hw->mac.type >= e1000_pch_spt) {
 			u16 data;
@@ -1462,14 +1460,14 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 			if (speed == SPEED_1000) {
 				ret_val = hw->phy.ops.acquire(hw);
 				if (ret_val)
-					return ret_val;
+					goto out;
 
 				ret_val = e1e_rphy_locked(hw,
 							  PHY_REG(776, 20),
 							  &data);
 				if (ret_val) {
 					hw->phy.ops.release(hw);
-					return ret_val;
+					goto out;
 				}
 
 				ptr_gap = (data & (0x3FF << 2)) >> 2;
@@ -1483,18 +1481,18 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 				}
 				hw->phy.ops.release(hw);
 				if (ret_val)
-					return ret_val;
+					goto out;
 			} else {
 				ret_val = hw->phy.ops.acquire(hw);
 				if (ret_val)
-					return ret_val;
+					goto out;
 
 				ret_val = e1e_wphy_locked(hw,
 							  PHY_REG(776, 20),
 							  0xC023);
 				hw->phy.ops.release(hw);
 				if (ret_val)
-					return ret_val;
+					goto out;
 
 			}
 		}
@@ -1521,7 +1519,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	    (hw->adapter->pdev->device == E1000_DEV_ID_PCH_I218_V3)) {
 		ret_val = e1000_k1_workaround_lpt_lp(hw, link);
 		if (ret_val)
-			return ret_val;
+			goto out;
 	}
 	if (hw->mac.type >= e1000_pch_lpt) {
 		/* Set platform power management values for
@@ -1529,7 +1527,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 		 */
 		ret_val = e1000_platform_pm_pch_lpt(hw, link);
 		if (ret_val)
-			return ret_val;
+			goto out;
 	}
 
 	/* Clear link partner's EEE ability */
@@ -1552,9 +1550,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	}
 
 	if (!link)
-		return 0;	/* No link detected */
-
-	mac->get_link_status = false;
+		goto out;
 
 	switch (hw->mac.type) {
 	case e1000_pch2lan:
@@ -1602,7 +1598,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * we have already determined whether we have link or not.
 	 */
 	if (!mac->autoneg)
-		return 1;
+		return -E1000_ERR_CONFIG;
 
 	/* Auto-Neg is enabled.  Auto Speed Detection takes care
 	 * of MAC speed/duplex configuration.  So we only need to
@@ -1616,12 +1612,14 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * different link partner.
 	 */
 	ret_val = e1000e_config_fc_after_link_up(hw);
-	if (ret_val) {
+	if (ret_val)
 		e_dbg("Error configuring flow control\n");
-		return ret_val;
-	}
 
-	return 1;
+	return ret_val;
+
+out:
+	mac->get_link_status = true;
+	return ret_val;
 }
 
 static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index db735644b312..5bdc3a2d4fd7 100644
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -410,9 +410,6 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
  *  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.
- *
- *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- *  up).
  **/
 s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 {
@@ -426,20 +423,16 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 	 * Change or Rx Sequence Error interrupt.
 	 */
 	if (!mac->get_link_status)
-		return 1;
+		return 0;
+	mac->get_link_status = false;
 
 	/* 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)
-		return ret_val;
-
-	if (!link)
-		return 0;	/* No link detected */
-
-	mac->get_link_status = false;
+	if (ret_val || !link)
+		goto out;
 
 	/* Check if there was DownShift, must be checked
 	 * immediately after link-up
@@ -450,7 +443,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 	 * we have already determined whether we have link or not.
 	 */
 	if (!mac->autoneg)
-		return 1;
+		return -E1000_ERR_CONFIG;
 
 	/* Auto-Neg is enabled.  Auto Speed Detection takes care
 	 * of MAC speed/duplex configuration.  So we only need to
@@ -464,12 +457,14 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 	 * different link partner.
 	 */
 	ret_val = e1000e_config_fc_after_link_up(hw);
-	if (ret_val) {
+	if (ret_val)
 		e_dbg("Error configuring flow control\n");
-		return ret_val;
-	}
 
-	return 1;
+	return ret_val;
+
+out:
+	mac->get_link_status = true;
+	return ret_val;
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c0f23446bf26..dc853b0863af 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5090,7 +5090,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter)
 	case e1000_media_type_copper:
 		if (hw->mac.get_link_status) {
 			ret_val = hw->mac.ops.check_for_link(hw);
-			link_active = ret_val > 0;
+			link_active = !hw->mac.get_link_status;
 		} else {
 			link_active = true;
 		}