cxgb3 - Fix I/O synchronization

Synchronize memory access before ringing
the Tx door bell.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 7b13d8a31e38..666c317dc6d6 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -174,6 +174,7 @@ static inline struct sge_qset *txq_to_qset(const struct sge_txq *q, int qidx)
 static inline void refill_rspq(struct adapter *adapter,
                                const struct sge_rspq *q, unsigned int credits)
 {
+        rmb();
         t3_write_reg(adapter, A_SG_RSPQ_CREDIT_RETURN,
                      V_RSPQ(q->cntxt_id) | V_CREDITS(credits));
 }
@@ -458,7 +459,7 @@ nomem:				q->alloc_failed++;
                 }
                 q->credits++;
         }
-
+        wmb();
         t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
 }
 
@@ -1353,6 +1354,7 @@ static void restart_ctrlq(unsigned long data)
         }
 
         spin_unlock(&q->lock);
+        wmb();
         t3_write_reg(qs->adap, A_SG_KDOORBELL,
                      F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
 }
@@ -1572,6 +1574,7 @@ static void restart_offloadq(unsigned long data)
         set_bit(TXQ_RUNNING, &q->flags);
         set_bit(TXQ_LAST_PKT_DB, &q->flags);
 #endif
+        wmb();
         t3_write_reg(adap, A_SG_KDOORBELL,
                      F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
 }
@@ -1737,7 +1740,6 @@ static inline int rx_offload(struct t3cdev *tdev, struct sge_rspq *rq,
                              struct sk_buff *skb, struct sk_buff *rx_gather[],
                              unsigned int gather_idx)
 {
-        rq->offload_pkts++;
         skb_reset_mac_header(skb);
         skb_reset_network_header(skb);
         skb_reset_transport_header(skb);
@@ -2031,6 +2033,7 @@ no_mem:
                         if (eth)
                                 rx_eth(adap, q, skb, ethpad);
                         else {
+                                q->offload_pkts++;
                                 /* Preserve the RSS info in csum & priority */
                                 skb->csum = rss_hi;
                                 skb->priority = rss_lo;