e1000e: Fix Hardware Unit Hang

[cascardo/linux.git] / drivers / net / ethernet / intel / e1000e / netdev.c

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index eafad41..d577723 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1090,8 +1090,14 @@ static void e1000_print_hw_hang(struct work_struct *work)
                adapter->tx_hang_recheck = true;
                return;
        }
-       /* Real hang detected */
        adapter->tx_hang_recheck = false;
+
+       if (er32(TDH(0)) == er32(TDT(0))) {
+               e_dbg("false hang detected, ignoring\n");
+               return;
+       }
+
+       /* Real hang detected */
        netif_stop_queue(netdev);
 
        e1e_rphy(hw, MII_BMSR, &phy_status);
@@ -1121,6 +1127,8 @@ static void e1000_print_hw_hang(struct work_struct *work)
              eop, jiffies, eop_desc->upper.fields.status, er32(STATUS),
              phy_status, phy_1000t_status, phy_ext_status, pci_status);
 
+       e1000e_dump(adapter);
+
        /* Suggest workaround for known h/w issue */
        if ((hw->mac.type == e1000_pchlan) && (er32(CTRL) & E1000_CTRL_TFCE))
                e_err("Try turning off Tx pause (flow control) via ethtool\n");
@@ -4798,6 +4806,7 @@ static void e1000e_check_82574_phy_workaround(struct e1000_adapter *adapter)
 
        if (adapter->phy_hang_count > 1) {
                adapter->phy_hang_count = 0;
+               e_dbg("PHY appears hung - resetting\n");
                schedule_work(&adapter->reset_task);
        }
 }
@@ -4956,15 +4965,11 @@ static void e1000_watchdog_task(struct work_struct *work)
                                mod_timer(&adapter->phy_info_timer,
                                          round_jiffies(jiffies + 2 * HZ));
 
-                       /* The link is lost so the controller stops DMA.
-                        * If there is queued Tx work that cannot be done
-                        * or if on an 8000ES2LAN which requires a Rx packet
-                        * buffer work-around on link down event, reset the
-                        * controller to flush the Tx/Rx packet buffers.
-                        * (Do the reset outside of interrupt context).
+                       /* 8000ES2LAN requires a Rx packet buffer work-around
+                        * on link down event; reset the controller to flush
+                        * the Rx packet buffer.
                         */
-                       if ((adapter->flags & FLAG_RX_NEEDS_RESTART) ||
-                           (e1000_desc_unused(tx_ring) + 1 < tx_ring->count))
+                       if (adapter->flags & FLAG_RX_NEEDS_RESTART)
                                adapter->flags |= FLAG_RESTART_NOW;
                        else
                                pm_schedule_suspend(netdev->dev.parent,
@@ -4987,6 +4992,15 @@ link_up:
        adapter->gotc_old = adapter->stats.gotc;
        spin_unlock(&adapter->stats64_lock);
 
+       /* If the link is lost the controller stops DMA, but
+        * if there is queued Tx work it cannot be done.  So
+        * reset the controller to flush the Tx packet buffers.
+        */
+       if (!netif_carrier_ok(netdev) &&
+           (e1000_desc_unused(tx_ring) + 1 < tx_ring->count))
+               adapter->flags |= FLAG_RESTART_NOW;
+
+       /* If reset is necessary, do it outside of interrupt context. */
        if (adapter->flags & FLAG_RESTART_NOW) {
                schedule_work(&adapter->reset_task);
                /* return immediately since reset is imminent */