bnx2x: napi_poll budget check

[safe/jmp/linux-2.6] / drivers / net / bnx2x_main.c

diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index e4d54e1..e0851a7 100644 (file)
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -874,7 +874,7 @@ static inline u16 bnx2x_tx_avail(struct bnx2x_fastpath *fp)
        return (s16)(fp->bp->tx_ring_size) - used;
 }
 
-static void bnx2x_tx_int(struct bnx2x_fastpath *fp, int work)
+static void bnx2x_tx_int(struct bnx2x_fastpath *fp)
 {
        struct bnx2x *bp = fp->bp;
        struct netdev_queue *txq;
@@ -908,9 +908,6 @@ static void bnx2x_tx_int(struct bnx2x_fastpath *fp, int work)
                bd_cons = bnx2x_free_tx_pkt(bp, fp, pkt_cons);
                sw_cons++;
                done++;
-
-               if (done == work)
-                       break;
        }
 
        fp->tx_pkt_cons = sw_cons;
@@ -4177,7 +4174,7 @@ static void bnx2x_timer(unsigned long data)
                struct bnx2x_fastpath *fp = &bp->fp[0];
                int rc;
 
-               bnx2x_tx_int(fp, 1000);
+               bnx2x_tx_int(fp);
                rc = bnx2x_rx_int(fp, 1000);
        }
 
@@ -7217,7 +7214,7 @@ static int bnx2x_nic_unload(struct bnx2x *bp, int unload_mode)
                cnt = 1000;
                while (bnx2x_has_tx_work_unload(fp)) {
 
-                       bnx2x_tx_int(fp, 1000);
+                       bnx2x_tx_int(fp);
                        if (!cnt) {
                                BNX2X_ERR("timeout waiting for queue[%d]\n",
                                          i);
@@ -10069,16 +10066,29 @@ static int bnx2x_poll(struct napi_struct *napi, int budget)
        bnx2x_update_fpsb_idx(fp);
 
        if (bnx2x_has_tx_work(fp))
-               bnx2x_tx_int(fp, budget);
+               bnx2x_tx_int(fp);
 
-       if (bnx2x_has_rx_work(fp))
+       if (bnx2x_has_rx_work(fp)) {
                work_done = bnx2x_rx_int(fp, budget);
 
-       rmb(); /* BNX2X_HAS_WORK() reads the status block */
+               /* must not complete if we consumed full budget */
+               if (work_done >= budget)
+                       goto poll_again;
+       }
 
-       /* must not complete if we consumed full budget */
-       if ((work_done < budget) && !BNX2X_HAS_WORK(fp)) {
+       /* BNX2X_HAS_WORK() reads the status block, thus we need to
+        * ensure that status block indices have been actually read
+        * (bnx2x_update_fpsb_idx) prior to this check (BNX2X_HAS_WORK)
+        * so that we won't write the "newer" value of the status block to IGU
+        * (if there was a DMA right after BNX2X_HAS_WORK and
+        * if there is no rmb, the memory reading (bnx2x_update_fpsb_idx)
+        * may be postponed to right before bnx2x_ack_sb). In this case
+        * there will never be another interrupt until there is another update
+        * of the status block, while there is still unhandled work.
+        */
+       rmb();
 
+       if (!BNX2X_HAS_WORK(fp)) {
 #ifdef BNX2X_STOP_ON_ERROR
 poll_panic:
 #endif
@@ -10090,6 +10100,7 @@ poll_panic:
                             le16_to_cpu(fp->fp_c_idx), IGU_INT_ENABLE, 1);
        }
 
+poll_again:
        return work_done;
 }