[BNX2]: Fix bug when rx ring is full

Fix the rx code path that does not handle the full rx ring correctly.

When the rx ring is set to the max. size (i.e. 255), the consumer and
producer indices will be the same when completing an rx packet. Fix
the rx code to handle this condition properly.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bnx2.c

@@ -1656,23 +1656,30 @@ static inline void
 bnx2_reuse_rx_skb(struct bnx2 *bp, struct sk_buff *skb,
 	u16 cons, u16 prod)
 {
-	struct sw_bd *cons_rx_buf = &bp->rx_buf_ring[cons];
-	struct sw_bd *prod_rx_buf = &bp->rx_buf_ring[prod];
-	struct rx_bd *cons_bd = &bp->rx_desc_ring[cons];
-	struct rx_bd *prod_bd = &bp->rx_desc_ring[prod];
+	struct sw_bd *cons_rx_buf, *prod_rx_buf;
+	struct rx_bd *cons_bd, *prod_bd;
+
+	cons_rx_buf = &bp->rx_buf_ring[cons];
+	prod_rx_buf = &bp->rx_buf_ring[prod];
 
 	pci_dma_sync_single_for_device(bp->pdev,
 		pci_unmap_addr(cons_rx_buf, mapping),
 		bp->rx_offset + RX_COPY_THRESH, PCI_DMA_FROMDEVICE);
 
-	prod_rx_buf->skb = cons_rx_buf->skb;
-	pci_unmap_addr_set(prod_rx_buf, mapping,
-			pci_unmap_addr(cons_rx_buf, mapping));
+	bp->rx_prod_bseq += bp->rx_buf_use_size;
 
-	memcpy(prod_bd, cons_bd, 8);
+	prod_rx_buf->skb = skb;
 
-	bp->rx_prod_bseq += bp->rx_buf_use_size;
+	if (cons == prod)
+		return;
+
+	pci_unmap_addr_set(prod_rx_buf, mapping,
+			pci_unmap_addr(cons_rx_buf, mapping));
 
+	cons_bd = &bp->rx_desc_ring[cons];
+	prod_bd = &bp->rx_desc_ring[prod];
+	prod_bd->rx_bd_haddr_hi = cons_bd->rx_bd_haddr_hi;
+	prod_bd->rx_bd_haddr_lo = cons_bd->rx_bd_haddr_lo;
 }
 
 static int
@@ -1699,14 +1706,19 @@ bnx2_rx_int(struct bnx2 *bp, int budget)
 		u32 status;
 		struct sw_bd *rx_buf;
 		struct sk_buff *skb;
+		dma_addr_t dma_addr;
 
 		sw_ring_cons = RX_RING_IDX(sw_cons);
 		sw_ring_prod = RX_RING_IDX(sw_prod);
 
 		rx_buf = &bp->rx_buf_ring[sw_ring_cons];
 		skb = rx_buf->skb;
-		pci_dma_sync_single_for_cpu(bp->pdev,
-			pci_unmap_addr(rx_buf, mapping),
+
+		rx_buf->skb = NULL;
+
+		dma_addr = pci_unmap_addr(rx_buf, mapping);
+
+		pci_dma_sync_single_for_cpu(bp->pdev, dma_addr,
 			bp->rx_offset + RX_COPY_THRESH, PCI_DMA_FROMDEVICE);
 
 		rx_hdr = (struct l2_fhdr *) skb->data;
@@ -1747,8 +1759,7 @@ bnx2_rx_int(struct bnx2 *bp, int budget)
 			skb = new_skb;
 		}
 		else if (bnx2_alloc_rx_skb(bp, sw_ring_prod) == 0) {
-			pci_unmap_single(bp->pdev,
-				pci_unmap_addr(rx_buf, mapping),
+			pci_unmap_single(bp->pdev, dma_addr,
 				bp->rx_buf_use_size, PCI_DMA_FROMDEVICE);
 
 			skb_reserve(skb, bp->rx_offset);
@@ -1794,8 +1805,6 @@ bnx2_rx_int(struct bnx2 *bp, int budget)
 		rx_pkt++;
 
 next_rx:
-		rx_buf->skb = NULL;
-
 		sw_cons = NEXT_RX_BD(sw_cons);
 		sw_prod = NEXT_RX_BD(sw_prod);
 
@@ -3360,7 +3369,7 @@ bnx2_init_rx_ring(struct bnx2 *bp)
 	val = (u64) bp->rx_desc_mapping & 0xffffffff;
 	CTX_WR(bp, GET_CID_ADDR(RX_CID), BNX2_L2CTX_NX_BDHADDR_LO, val);
 
-	for ( ;ring_prod < bp->rx_ring_size; ) {
+	for (i = 0; i < bp->rx_ring_size; i++) {
 		if (bnx2_alloc_rx_skb(bp, ring_prod) < 0) {
 			break;
 		}