--- a/vordog.c	Tue Jul 08 16:06:24 2008 +0800
+++ b/vordog.c	Tue Jul 08 17:10:01 2008 +0800
@@ -201,21 +201,22 @@
  * after 4 times of initial value.  So, it only (i * 4) seconds in range
  * of 4 ~ (255 * 4), where i is one of positive integer, are supported.
  *
- * The supported time intervals of watchdog(9) are 2^31~2^39 nanoseconds.
+ * The supported time intervals of watchdog(9) are 2^32~2^39 nanoseconds.
  * vordog used a (i * 4) seconds for 2^n seconds while i * 4 seconds is
- * smallest one of intervals that bigger than 2^n seconds.
+ * closest to 2^n nanoseconds.  The variances between i * 4 seconds and
+ * 2^n nanoseconds are less than 7% (6.8678%).
  */
 static void
 vordog_wd9_evh(void *priv_data, u_int cmd, int *error) {
     vd_softc_t sc;
     u_int timeout, u;
-    /* 2^31, 2^32, ..., 2^39 nanoseconds */
-    static const int timeouts[] = { 1, 2, 3, 5, 9, 18, 35, 69, 138};
+    /* 2^32, 2^33, ..., 2^39 nanoseconds */
+    static const int timeouts[] = { 1, 2, 4, 9, 17, 34, 69, 137};
 
     sc = (vd_softc_t)priv_data;
 
     u = cmd & WD_INTERVAL;
-    if(u < 31 || u > 39) {
+    if(u < 32 || u > 39) {
 	/* Out of range! Can not be configured. */
 	vordog_wd9_disable();
 	sc->init_val = 0;