1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 7d824cf8ee2d..f296c37f29b6 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -217,9 +217,16 @@ static inline u32 bnx2_tx_avail(struct bnx2 *bp)
         u32 diff;
 
         smp_mb();
-        diff = TX_RING_IDX(bp->tx_prod) - TX_RING_IDX(bp->tx_cons);
-        if (diff > MAX_TX_DESC_CNT)
-                diff = (diff & MAX_TX_DESC_CNT) - 1;
+
+        /* The ring uses 256 indices for 255 entries, one of them
+         * needs to be skipped.
+         */
+        diff = bp->tx_prod - bp->tx_cons;
+        if (unlikely(diff >= TX_DESC_CNT)) {
+                diff &= 0xffff;
+                if (diff == TX_DESC_CNT)
+                        diff = MAX_TX_DESC_CNT;
+        }
         return (bp->tx_ring_size - diff);
 }