[PATCH 1/2] net/tg3.c: use mmiowb in tg3_rx, tg3_start_xmit

[<akepner@xxxxxxx>]

Using mmiowb() prevents an occasional oops in tg3_tx() resulting from 
a NULL skb pointer in the tx_ring_info structure.


Signed-off-by: Greg Banks <gnb@xxxxxxx>
---

--- linux.1/drivers/net/tg3.c   2004-10-12 13:50:39.000000000 -0700
+++ linux/drivers/net/tg3.c     2004-10-12 13:55:37.000000000 -0700
@@ -2729,6 +2729,7 @@
                tw32_rx_mbox(MAILBOX_RCV_JUMBO_PROD_IDX + TG3_64BIT_REG_LOW,
                             sw_idx);
        }
+       mmiowb();
 
        return received;
 }
@@ -3176,6 +3177,7 @@
                netif_stop_queue(dev);
 
 out_unlock:
+       mmiowb();
        spin_unlock_irqrestore(&tp->tx_lock, flags);
 
        dev->trans_start = jiffies;