diff --git a/sys/arm/ti/ti_mbox.c b/sys/arm/ti/ti_mbox.c
--- a/sys/arm/ti/ti_mbox.c
+++ b/sys/arm/ti/ti_mbox.c
@@ -174,6 +174,7 @@
 	sysconfig = ti_mbox_reg_read(sc, TI_MBOX_SYSCONFIG);
 	DPRINTF("initial sysconfig %d\n", sysconfig);
 	sysconfig |= TI_MBOX_SYSCONFIG_SOFTRST;
+	ti_mbox_reg_write(sc, TI_MBOX_SYSCONFIG, sysconfig);
 	delay = 100;
 	while (ti_mbox_reg_read(sc, TI_MBOX_SYSCONFIG) & 
 	    TI_MBOX_SYSCONFIG_SOFTRST) {