e1000e: i219 execute unit hang fix on every reset or power state transition

After testing various cases, the conclusion is that the fix MUST be
executed BEFORE any event that the HW is reset or transition to D3.
To fix that I moved the execution to the relevant places but per
Alexander Duyck's review, ensure now that the DMA is valid and was not
freed before manipulating the ring.

Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/netdev.c

@@ -4043,6 +4043,8 @@ void e1000e_reset(struct e1000_adapter *adapter)
 		}
 	}
 
+	if (hw->mac.type == e1000_pch_spt)
+		e1000_flush_desc_rings(adapter);
 	/* Allow time for pending master requests to run */
 	mac->ops.reset_hw(hw);
 
@@ -4215,10 +4217,6 @@ void e1000e_down(struct e1000_adapter *adapter, bool reset)
 	spin_unlock(&adapter->stats64_lock);
 
 	e1000e_flush_descriptors(adapter);
-	if (hw->mac.type == e1000_pch_spt)
-		e1000_flush_desc_rings(adapter);
-	e1000_clean_tx_ring(adapter->tx_ring);
-	e1000_clean_rx_ring(adapter->rx_ring);
 
 	adapter->link_speed = 0;
 	adapter->link_duplex = 0;
@@ -4229,8 +4227,14 @@ void e1000e_down(struct e1000_adapter *adapter, bool reset)
 	    e1000_lv_jumbo_workaround_ich8lan(hw, false))
 		e_dbg("failed to disable jumbo frame workaround mode\n");
 
-	if (reset && !pci_channel_offline(adapter->pdev))
-		e1000e_reset(adapter);
+	if (!pci_channel_offline(adapter->pdev)) {
+		if (reset)
+			e1000e_reset(adapter);
+		else if (hw->mac.type == e1000_pch_spt)
+			e1000_flush_desc_rings(adapter);
+	}
+	e1000_clean_tx_ring(adapter->tx_ring);
+	e1000_clean_rx_ring(adapter->rx_ring);
 }
 
 void e1000e_reinit_locked(struct e1000_adapter *adapter)