svn commit: r185355 - head/sys/dev/e1000

[Jack F Vogel]

Author: jfv
Date: Thu Nov 27 02:18:43 2008
New Revision: 185355
URL: http://svn.freebsd.org/changeset/base/185355

Log:
  Thanks to the reminder from Ganbold, small fix in the RX failure
  path for an infinite loop. Problem originally noticed in ixgbe
  by Jeff Roberson and fixed there. Thanks to everyone involved.

Modified:
  head/sys/dev/e1000/if_igb.c

Modified: head/sys/dev/e1000/if_igb.c
==============================================================================
--- head/sys/dev/e1000/if_igb.c	Thu Nov 27 01:57:23 2008	(r185354)
+++ head/sys/dev/e1000/if_igb.c	Thu Nov 27 02:18:43 2008	(r185355)
@@ -3490,12 +3490,11 @@ igb_setup_receive_ring(struct rx_ring *r
 	return (0);
 fail:
 	/*
-	 * We need to clean up any buffers allocated so far
-	 * 'j' is the failing index, decrement it to get the
-	 * last success.
+	 * We need to clean up any buffers allocated
+	 * so far, 'j' is the failing index.
 	 */
-	for (--j; j < 0; j--) {
-		rxbuf = &rxr->rx_buffers[j];
+	for (int i = 0; i < j; i++) {
+		rxbuf = &rxr->rx_buffers[i];
 		if (rxbuf->m_head != NULL) {
 			bus_dmamap_sync(rxr->rxtag, rxbuf->map,
 			    BUS_DMASYNC_POSTREAD);
@@ -3516,9 +3515,9 @@ static int
 igb_setup_receive_structures(struct adapter *adapter)
 {
 	struct rx_ring *rxr = adapter->rx_rings;
-	int i, j;
+	int j;
 
-	for (i = 0; i < adapter->num_rx_queues; i++, rxr++)
+	for (j = 0; j < adapter->num_rx_queues; j++, rxr++)
 		if (igb_setup_receive_ring(rxr))
 			goto fail;
 
@@ -3527,14 +3526,13 @@ fail:
 	/*
 	 * Free RX buffers allocated so far, we will only handle
 	 * the rings that completed, the failing case will have
-	 * cleaned up for itself. The value of 'i' will be the
-	 * failed ring so we must pre-decrement it.
+	 * cleaned up for itself. Clean up til 'j', the failure.
 	 */
-	rxr = adapter->rx_rings;
-	for (--i; i > 0; i--, rxr++) {
-		for (j = 0; j < adapter->num_rx_desc; j++) {
+	for (int i = 0; i < j; i++) {
+		rxr = &adapter->rx_rings[i];
+		for (int n = 0; n < adapter->num_rx_desc; n++) {
 			struct igb_buffer *rxbuf;
-			rxbuf = &rxr->rx_buffers[j];
+			rxbuf = &rxr->rx_buffers[n];
 			if (rxbuf->m_head != NULL) {
 				bus_dmamap_sync(rxr->rxtag, rxbuf->map,
 			  	  BUS_DMASYNC_POSTREAD);