After finishing with the received descriptor, make sure to "eieio" to make

sure the OWN gets back to the gmac in the proper order.  This reduces (and
maybe even fixes) the gm0 out-of-order problem.

sys/arch/macppc/dev/if_gm.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: if_gm.c,v 1.10 2000/12/28 22:59:09 sommerfeld Exp $	*/
+/*	$NetBSD: if_gm.c,v 1.11 2001/04/20 01:18:47 matt Exp $	*/
 
 /*-
  * Copyright (c) 2000 Tsubai Masanari.  All rights reserved.
@@ -398,6 +398,7 @@ next:
 		dp->cmd_hi = 0;
 		__asm __volatile ("sync");
 		dp->cmd = htole32(GMAC_OWN);
+		__asm __volatile ("eieio");	/* force out the OWN bit */
 	}
 	sc->sc_rxlast = i;
 }