--- linux-2.6.20/drivers/net/tg3.c.orig	2007-02-06 22:30:39.000000000 +0100
+++ linux-2.6.20-ed/drivers/net/tg3.c	2007-02-06 22:32:42.000000000 +0100
@@ -3384,7 +3384,7 @@
 		}
 next_pkt_nopost:
 		sw_idx++;
-		sw_idx %= TG3_RX_RCB_RING_SIZE(tp);
+		sw_idx &= (TG3_RX_RCB_RING_SIZE(tp) - 1);
 
 		/* Refresh hw_idx to see if there is new work */
 		if (sw_idx == hw_idx) {