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-rw-r--r--drivers/net/bnx2.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 7d824cf8ee2..f296c37f29b 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);
}