[IB/ipoib]: Fix unsigned comparisons to handle wraparound

Fix handling of tx_head/tx_tail comparisons to handle wraparound.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 8238766746b2c1c34d70768167541d7dd113460a..eee82363167da841c3aad9b56443bac922bceeb0 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -81,7 +81,7 @@ void ipoib_free_ah(struct kref *kref)
 
        unsigned long flags;
 
-       if (ah->last_send <= priv->tx_tail) {
+       if ((int) priv->tx_tail - (int) ah->last_send >= 0) {
                ipoib_dbg(priv, "Freeing ah %p\n", ah->ah);
                ib_destroy_ah(ah->ah);
                kfree(ah);
@@ -355,7 +355,7 @@ static void __ipoib_reap_ah(struct net_device *dev)
 
        spin_lock_irq(&priv->lock);
        list_for_each_entry_safe(ah, tah, &priv->dead_ahs, list)
-               if (ah->last_send <= priv->tx_tail) {
+               if ((int) priv->tx_tail - (int) ah->last_send >= 0) {
                        list_del(&ah->list);
                        list_add_tail(&ah->list, &remove_list);
                }
@@ -486,7 +486,7 @@ int ipoib_ib_dev_stop(struct net_device *dev)
                         * assume the HW is wedged and just free up
                         * all our pending work requests.
                         */
-                       while (priv->tx_tail < priv->tx_head) {
+                       while ((int) priv->tx_tail - (int) priv->tx_head < 0) {
                                tx_req = &priv->tx_ring[priv->tx_tail &
                                                        (IPOIB_TX_RING_SIZE - 1)];
                                dma_unmap_single(priv->ca->dma_device,