Index: sys/arch/evbarm/rpi/rpi_machdep.c
===================================================================
RCS file: /cvsroot/src/sys/arch/evbarm/rpi/rpi_machdep.c,v
retrieving revision 1.81
diff -u -p -r1.81 rpi_machdep.c
--- sys/arch/evbarm/rpi/rpi_machdep.c	4 Nov 2017 14:47:06 -0000	1.81
+++ sys/arch/evbarm/rpi/rpi_machdep.c	5 Nov 2017 15:30:04 -0000
@@ -648,20 +648,10 @@ rpi_bootstrap(void)
 		bus_space_write_4(iot, ioh,
 		    BCM2836_LOCAL_MAILBOX3_SETN(i),
 		    (uint32_t)cortex_mpstart);
-
-		int timeout = 20;
-		while (timeout-- > 0) {
-			uint32_t val;
-
-			val = bus_space_read_4(iot, ioh,
-			    BCM2836_LOCAL_MAILBOX3_CLRN(i));
-			if (val == 0)
-				break;
-		}
 	}
 
 	/* Wake up APs in case firmware has placed them in WFE state */
-	__asm __volatile("sev");
+	__asm __volatile("sev" ::: "memory");
 
 	for (int loop = 0; loop < 16; loop++) {
 		if (arm_cpu_hatched == __BITS(arm_cpu_max - 1, 1))