watchdog: Revert "iTCO_wdt: all versions count down twice"

This reverts commit 1fccb73011.
Reported as Bug 196509 - iTCO_wdt regression reboot before timeout expire

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Documentation/watchdog/watchdog-parameters.txt

@@ -117,7 +117,7 @@ nowayout: Watchdog cannot be stopped once started
 -------------------------------------------------
 iTCO_wdt:
 heartbeat: Watchdog heartbeat in seconds.
-	(5<=heartbeat<=74 (TCO v1) or 1226 (TCO v2), default=30)
+	(2<heartbeat<39 (TCO v1) or 613 (TCO v2), default=30)
 nowayout: Watchdog cannot be stopped once started
 	(default=kernel config parameter)
 -------------------------------------------------

drivers/watchdog/iTCO_wdt.c

@@ -306,15 +306,16 @@ static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
 
 	iTCO_vendor_pre_keepalive(p->smi_res, wd_dev->timeout);
 
-	/* Reset the timeout status bit so that the timer
-	 * needs to count down twice again before rebooting */
-	outw(0x0008, TCO1_STS(p));	/* write 1 to clear bit */
-
 	/* Reload the timer by writing to the TCO Timer Counter register */
-	if (p->iTCO_version >= 2)
+	if (p->iTCO_version >= 2) {
 		outw(0x01, TCO_RLD(p));
-	else if (p->iTCO_version == 1)
+	} else if (p->iTCO_version == 1) {
+		/* Reset the timeout status bit so that the timer
+		 * needs to count down twice again before rebooting */
+		outw(0x0008, TCO1_STS(p));	/* write 1 to clear bit */
+
 		outb(0x01, TCO_RLD(p));
+	}
 
 	spin_unlock(&p->io_lock);
 	return 0;
@@ -327,8 +328,11 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
 	unsigned char val8;
 	unsigned int tmrval;
 
-	/* The timer counts down twice before rebooting */
-	tmrval = seconds_to_ticks(p, t) / 2;
+	tmrval = seconds_to_ticks(p, t);
+
+	/* For TCO v1 the timer counts down twice before rebooting */
+	if (p->iTCO_version == 1)
+		tmrval /= 2;
 
 	/* from the specs: */
 	/* "Values of 0h-3h are ignored and should not be attempted" */
@@ -381,8 +385,6 @@ static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
 		spin_lock(&p->io_lock);
 		val16 = inw(TCO_RLD(p));
 		val16 &= 0x3ff;
-		if (!(inw(TCO1_STS(p)) & 0x0008))
-			val16 += (inw(TCOv2_TMR(p)) & 0x3ff);
 		spin_unlock(&p->io_lock);
 
 		time_left = ticks_to_seconds(p, val16);