Subject: [PATCH 1/2] sky2: fix transmit DMA map leakage

From: Stephen Hemminger <[email-masked]>
Date: Mon, 1 Feb 2010 15:41:47 -0800

The book keeping structure for transmit always had the flags value
cleared so transmit DMA maps were never released correctly.
Based on patch by Jarek Poplawski, problem observed by Michael Breuer.

Signed-off-by: Stephen Hemminger <[email-masked]>

--
This patch is against net-next but it should go to 2.6.33 and stable
as well.

--- a/drivers/net/sky2.c	2010-02-01 10:07:42.676296236 -0800
+++ b/drivers/net/sky2.c	2010-02-01 10:18:12.575044064 -0800
@@ -1025,11 +1025,8 @@ static void sky2_prefetch_init(struct sk
 static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot)
 {
 	struct sky2_tx_le *le = sky2->tx_le + *slot;
-	struct tx_ring_info *re = sky2->tx_ring + *slot;
 
 	*slot = RING_NEXT(*slot, sky2->tx_ring_size);
-	re->flags = 0;
-	re->skb = NULL;
 	le->ctrl = 0;
 	return le;
 }
@@ -1622,8 +1619,7 @@ static unsigned tx_le_req(const struct s
 	return count;
 }
 
-static void sky2_tx_unmap(struct pci_dev *pdev,
-			  const struct tx_ring_info *re)
+static void sky2_tx_unmap(struct pci_dev *pdev, struct tx_ring_info *re)
 {
 	if (re->flags & TX_MAP_SINGLE)
 		pci_unmap_single(pdev, pci_unmap_addr(re, mapaddr),
@@ -1633,6 +1629,7 @@ static void sky2_tx_unmap(struct pci_dev
 		pci_unmap_page(pdev, pci_unmap_addr(re, mapaddr),
 			       pci_unmap_len(re, maplen),
 			       PCI_DMA_TODEVICE);
+	re->flags = 0;
 }
 
 /*
@@ -1839,6 +1836,7 @@ static void sky2_tx_complete(struct sky2
 			dev->stats.tx_packets++;
 			dev->stats.tx_bytes += skb->len;
 
+			re->skb = NULL;
 			dev_kfree_skb_any(skb);
 
 			sky2->tx_next = RING_NEXT(idx, sky2->tx_ring_size);