1 files changed, 33 insertions, 17 deletions

diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index 0687c6aa4e46..fad8f9ea0043 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -2769,25 +2769,38 @@ void e1000e_reset(struct e1000_adapter *adapter)
 	/*
 	 * flow control settings
 	 *
-	 * The high water mark must be low enough to fit two full frame
+	 * The high water mark must be low enough to fit one full frame
 	 * (or the size used for early receive) above it in the Rx FIFO.
 	 * Set it to the lower of:
 	 * - 90% of the Rx FIFO size, and
 	 * - the full Rx FIFO size minus the early receive size (for parts
 	 *   with ERT support assuming ERT set to E1000_ERT_2048), or
-	 * - the full Rx FIFO size minus two full frames
+	 * - the full Rx FIFO size minus one full frame
 	 */
-	if ((adapter->flags & FLAG_HAS_ERT) &&
-	    (adapter->netdev->mtu > ETH_DATA_LEN))
-		hwm = min(((pba << 10) * 9 / 10),
-			  ((pba << 10) - (E1000_ERT_2048 << 3)));
-	else
-		hwm = min(((pba << 10) * 9 / 10),
-			  ((pba << 10) - (2 * adapter->max_frame_size)));
+	if (hw->mac.type == e1000_pchlan) {
+		/*
+		 * Workaround PCH LOM adapter hangs with certain network
+		 * loads.  If hangs persist, try disabling Tx flow control.
+		 */
+		if (adapter->netdev->mtu > ETH_DATA_LEN) {
+			fc->high_water = 0x3500;
+			fc->low_water  = 0x1500;
+		} else {
+			fc->high_water = 0x5000;
+			fc->low_water  = 0x3000;
+		}
+	} else {
+		if ((adapter->flags & FLAG_HAS_ERT) &&
+		    (adapter->netdev->mtu > ETH_DATA_LEN))
+			hwm = min(((pba << 10) * 9 / 10),
+				  ((pba << 10) - (E1000_ERT_2048 << 3)));
+		else
+			hwm = min(((pba << 10) * 9 / 10),
+				  ((pba << 10) - adapter->max_frame_size));
 
-	fc->high_water = hwm & E1000_FCRTH_RTH; /* 8-byte granularity */
-	fc->low_water = (fc->high_water - (2 * adapter->max_frame_size));
-	fc->low_water &= E1000_FCRTL_RTL; /* 8-byte granularity */
+		fc->high_water = hwm & E1000_FCRTH_RTH; /* 8-byte granularity */
+		fc->low_water = fc->high_water - 8;
+	}
 
 	if (adapter->flags & FLAG_DISABLE_FC_PAUSE_TIME)
 		fc->pause_time = 0xFFFF;
@@ -2813,6 +2826,10 @@ void e1000e_reset(struct e1000_adapter *adapter)
 	if (mac->ops.init_hw(hw))
 		e_err("Hardware Error\n");
 
+	/* additional part of the flow-control workaround above */
+	if (hw->mac.type == e1000_pchlan)
+		ew32(FCRTV_PCH, 0x1000);
+
 	e1000_update_mng_vlan(adapter);
 
 	/* Enable h/w to recognize an 802.1Q VLAN Ethernet packet */
@@ -3610,7 +3627,7 @@ static void e1000_watchdog_task(struct work_struct *work)
 			case SPEED_100:
 				txb2b = 0;
 				netdev->tx_queue_len = 100;
-				/* maybe add some timeout factor ? */
+				adapter->tx_timeout_factor = 10;
 				break;
 			}
 
@@ -4288,8 +4305,10 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 
 	while (test_and_set_bit(__E1000_RESETTING, &adapter->state))
 		msleep(1);
-	/* e1000e_down has a dependency on max_frame_size */
+	/* e1000e_down -> e1000e_reset dependent on max_frame_size & mtu */
 	adapter->max_frame_size = max_frame;
+	e_info("changing MTU from %d to %d\n", netdev->mtu, new_mtu);
+	netdev->mtu = new_mtu;
 	if (netif_running(netdev))
 		e1000e_down(adapter);
 
@@ -4319,9 +4338,6 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 		adapter->rx_buffer_len = ETH_FRAME_LEN + VLAN_HLEN
 					 + ETH_FCS_LEN;
 
-	e_info("changing MTU from %d to %d\n", netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
-
 	if (netif_running(netdev))
 		e1000e_up(adapter);
 	else