Index: em_txrx.c
===================================================================
--- em_txrx.c	(revision 311989)
+++ em_txrx.c	(working copy)
@@ -404,6 +404,7 @@
 	int last, done;
 	struct em_txbuffer *buf;
 	struct e1000_tx_desc *tx_desc, *eop_desc;
+	int limit;
 
 	cidx = cidx_init;
 	buf = &txr->tx_buffers[cidx];
@@ -410,6 +411,7 @@
 	tx_desc = &txr->tx_base[cidx];
         last = buf->eop;
 	eop_desc = &txr->tx_base[last];
+	limit = adapter->tx_process_limit;
 
 	DPRINTF(iflib_get_dev(adapter->ctx), "credits_update: cidx_init=%d clear=%d last=%d\n",
 		      cidx_init, clear, last);
@@ -424,7 +426,7 @@
 	done = last;
 
 
-	while (eop_desc->upper.fields.status & E1000_TXD_STAT_DD) {
+	while (limit && (eop_desc->upper.fields.status & E1000_TXD_STAT_DD)) {
 		/* We clean the range of the packet */
 		while (cidx != done) {
 			if (clear) {
@@ -453,6 +455,7 @@
 		if (++last == scctx->isc_ntxd[0])
 			last = 0;
 		done = last;
+		limit--;
 	}
 
 	DPRINTF(iflib_get_dev(adapter->ctx), "Processed %d credits update\n", processed);