sky2: Avoid rewinding sky2->tx_prod

Keep sky2->tx_prod consistent since int might be examined by
an softirq poll or restart.

Signed-off-by: Mike McCormack <mikem@ring3k.org>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 1415a8375093..a52b86317837 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -989,11 +989,11 @@ static void sky2_prefetch_init(struct sky2_hw *hw, u32 qaddr,
         sky2_read32(hw, Y2_QADDR(qaddr, PREF_UNIT_CTRL));
 }
 
-static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2)
+static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot)
 {
-        struct sky2_tx_le *le = sky2->tx_le + sky2->tx_prod;
+        struct sky2_tx_le *le = sky2->tx_le + *slot;
 
-        sky2->tx_prod = RING_NEXT(sky2->tx_prod, TX_RING_SIZE);
+        *slot = RING_NEXT(*slot, TX_RING_SIZE);
         le->ctrl = 0;
         return le;
 }
@@ -1006,7 +1006,7 @@ static void tx_init(struct sky2_port *sky2)
         sky2->tx_tcpsum = 0;
         sky2->tx_last_mss = 0;
 
-        le = get_tx_le(sky2);
+        le = get_tx_le(sky2, &sky2->tx_prod);
         le->addr = 0;
         le->opcode = OP_ADDR64 | HW_OWNER;
 }
@@ -1572,7 +1572,8 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         struct sky2_hw *hw = sky2->hw;
         struct sky2_tx_le *le = NULL;
         struct tx_ring_info *re;
-        unsigned i, len, first_slot;
+        unsigned i, len;
+        u16 slot;
         dma_addr_t mapping;
         u16 mss;
         u8 ctrl;
@@ -1586,14 +1587,14 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         if (pci_dma_mapping_error(hw->pdev, mapping))
                 goto mapping_error;
 
-        first_slot = sky2->tx_prod;
+        slot = sky2->tx_prod;
         if (unlikely(netif_msg_tx_queued(sky2)))
                 printk(KERN_DEBUG "%s: tx queued, slot %u, len %d\n",
-                       dev->name, first_slot, skb->len);
+                       dev->name, slot, skb->len);
 
         /* Send high bits if needed */
         if (sizeof(dma_addr_t) > sizeof(u32)) {
-                le = get_tx_le(sky2);
+                le = get_tx_le(sky2, &slot);
                 le->addr = cpu_to_le32(upper_32_bits(mapping));
                 le->opcode = OP_ADDR64 | HW_OWNER;
         }
@@ -1606,7 +1607,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
                         mss += ETH_HLEN + ip_hdrlen(skb) + tcp_hdrlen(skb);
 
                 if (mss != sky2->tx_last_mss) {
-                        le = get_tx_le(sky2);
+                        le = get_tx_le(sky2, &slot);
                         le->addr = cpu_to_le32(mss);
 
                         if (hw->flags & SKY2_HW_NEW_LE)
@@ -1622,7 +1623,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         /* Add VLAN tag, can piggyback on LRGLEN or ADDR64 */
         if (sky2->vlgrp && vlan_tx_tag_present(skb)) {
                 if (!le) {
-                        le = get_tx_le(sky2);
+                        le = get_tx_le(sky2, &slot);
                         le->addr = 0;
                         le->opcode = OP_VLAN|HW_OWNER;
                 } else
@@ -1651,7 +1652,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
                         if (tcpsum != sky2->tx_tcpsum) {
                                 sky2->tx_tcpsum = tcpsum;
 
-                                le = get_tx_le(sky2);
+                                le = get_tx_le(sky2, &slot);
                                 le->addr = cpu_to_le32(tcpsum);
                                 le->length = 0; /* initial checksum value */
                                 le->ctrl = 1;   /* one packet */
@@ -1660,7 +1661,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
                 }
         }
 
-        le = get_tx_le(sky2);
+        le = get_tx_le(sky2, &slot);
         le->addr = cpu_to_le32((u32) mapping);
         le->length = cpu_to_le16(len);
         le->ctrl = ctrl;
@@ -1681,13 +1682,13 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
                         goto mapping_unwind;
 
                 if (sizeof(dma_addr_t) > sizeof(u32)) {
-                        le = get_tx_le(sky2);
+                        le = get_tx_le(sky2, &slot);
                         le->addr = cpu_to_le32(upper_32_bits(mapping));
                         le->ctrl = 0;
                         le->opcode = OP_ADDR64 | HW_OWNER;
                 }
 
-                le = get_tx_le(sky2);
+                le = get_tx_le(sky2, &slot);
                 le->addr = cpu_to_le32((u32) mapping);
                 le->length = cpu_to_le16(frag->size);
                 le->ctrl = ctrl;
@@ -1701,6 +1702,8 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 
         le->ctrl |= EOP;
 
+        sky2->tx_prod = slot;
+
         if (tx_avail(sky2) <= MAX_SKB_TX_LE)
                 netif_stop_queue(dev);
 
@@ -1709,7 +1712,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         return NETDEV_TX_OK;
 
 mapping_unwind:
-        for (i = first_slot; i != sky2->tx_prod; i = RING_NEXT(i, TX_RING_SIZE)) {
+        for (i = sky2->tx_prod; i != slot; i = RING_NEXT(i, TX_RING_SIZE)) {
                 le = sky2->tx_le + i;
                 re = sky2->tx_ring + i;
 
@@ -1729,7 +1732,6 @@ mapping_unwind:
                 }
         }
 
-        sky2->tx_prod = first_slot;
 mapping_error:
         if (net_ratelimit())
                 dev_warn(&hw->pdev->dev, "%s: tx mapping error\n", dev->name);