[PATCH] e1000: flow control

* Bug fix: flow control high/low watermark settings not
  within Rx FIFO range: math error.

drivers/net/e1000/e1000.h

@@ -113,7 +113,7 @@ struct e1000_adapter;
 #define E1000_SMARTSPEED_MAX       15
 
 /* Packet Buffer allocations */
-#define E1000_TX_FIFO_SIZE_SHIFT 0xA
+#define E1000_PBA_BYTES_SHIFT 0xA
 #define E1000_TX_HEAD_ADDR_SHIFT 7
 #define E1000_PBA_TX_MASK 0xFFFF0000
 

drivers/net/e1000/e1000_main.c

@@ -328,14 +328,16 @@ e1000_reset(struct e1000_adapter *adapter)
 		adapter->tx_fifo_head = 0;
 		adapter->tx_head_addr = pba << E1000_TX_HEAD_ADDR_SHIFT;
 		adapter->tx_fifo_size =
-			(E1000_PBA_40K - pba) << E1000_TX_FIFO_SIZE_SHIFT;
+			(E1000_PBA_40K - pba) << E1000_PBA_BYTES_SHIFT;
 		atomic_set(&adapter->tx_fifo_stall, 0);
 	}
 	E1000_WRITE_REG(&adapter->hw, PBA, pba);
 
 	/* flow control settings */
-	adapter->hw.fc_high_water = pba - E1000_FC_HIGH_DIFF;
-	adapter->hw.fc_low_water = pba - E1000_FC_LOW_DIFF;
+	adapter->hw.fc_high_water =
+		(pba << E1000_PBA_BYTES_SHIFT) - E1000_FC_HIGH_DIFF;
+	adapter->hw.fc_low_water =
+		(pba << E1000_PBA_BYTES_SHIFT) - E1000_FC_LOW_DIFF;
 	adapter->hw.fc_pause_time = E1000_FC_PAUSE_TIME;
 	adapter->hw.fc_send_xon = 1;
 	adapter->hw.fc = adapter->hw.original_fc;