svn commit: r205949 - head/sys/dev/cxgb

[Navdeep Parhar]

Author: np
Date: Wed Mar 31 00:26:35 2010
New Revision: 205949
URL: http://svn.freebsd.org/changeset/base/205949

Log:
  Fix signed/unsigned mix-up that allowed txq->in_use to grow beyond txq->size.

Modified:
  head/sys/dev/cxgb/cxgb_sge.c

Modified: head/sys/dev/cxgb/cxgb_sge.c
==============================================================================
--- head/sys/dev/cxgb/cxgb_sge.c	Wed Mar 31 00:26:02 2010	(r205948)
+++ head/sys/dev/cxgb/cxgb_sge.c	Wed Mar 31 00:26:35 2010	(r205949)
@@ -1638,12 +1638,9 @@ cxgb_start_locked(struct sge_qset *qs)
 {
 	struct mbuf *m_head = NULL;
 	struct sge_txq *txq = &qs->txq[TXQ_ETH];
-	int avail, txmax;
 	int in_use_init = txq->in_use;
 	struct port_info *pi = qs->port;
 	struct ifnet *ifp = pi->ifp;
-	avail = txq->size - txq->in_use - 4;
-	txmax = min(TX_START_MAX_DESC, avail);
 
 	if (qs->qs_flags & (QS_FLUSHING|QS_TIMEOUT))
 		reclaim_completed_tx(qs, 0, TXQ_ETH);
@@ -1653,12 +1650,14 @@ cxgb_start_locked(struct sge_qset *qs)
 		return;
 	}
 	TXQ_LOCK_ASSERT(qs);
-	while ((txq->in_use - in_use_init < txmax) &&
-	    !TXQ_RING_EMPTY(qs) &&
-	    (ifp->if_drv_flags & IFF_DRV_RUNNING) &&
+	while ((txq->in_use - in_use_init < TX_START_MAX_DESC) &&
+	    !TXQ_RING_EMPTY(qs) && (ifp->if_drv_flags & IFF_DRV_RUNNING) &&
 	    pi->link_config.link_ok) {
 		reclaim_completed_tx(qs, cxgb_tx_reclaim_threshold, TXQ_ETH);
 
+		if (txq->size - txq->in_use <= TX_MAX_DESC)
+			break;
+
 		if ((m_head = cxgb_dequeue(qs)) == NULL)
 			break;
 		/*
@@ -1697,7 +1696,7 @@ cxgb_transmit_locked(struct ifnet *ifp, 
 	 * - there is space in hardware transmit queue 
 	 */
 	if (check_pkt_coalesce(qs) == 0 &&
-	    !TXQ_RING_NEEDS_ENQUEUE(qs) && avail > 4) {
+	    !TXQ_RING_NEEDS_ENQUEUE(qs) && avail > TX_MAX_DESC) {
 		if (t3_encap(qs, &m)) {
 			if (m != NULL &&
 			    (error = drbr_enqueue(ifp, br, m)) != 0)