Index: linus-2.6/drivers/macintosh/therm_adt746x.c
===================================================================
--- linus-2.6.orig/drivers/macintosh/therm_adt746x.c	2007-07-16 12:56:25.000000000 -0400
+++ linus-2.6/drivers/macintosh/therm_adt746x.c	2007-07-16 14:08:08.000000000 -0400
@@ -278,26 +278,34 @@
 
 static void update_fans_speed (struct thermostat *th)
 {
-	int lastvar = 0; /* last variation, for iBook */
-	int i = 0;
+	int sensor, fan, adt7460, vars[2] = { -50, -50 };
+
+	adt7460 = (therm_type == ADT7460);
 
 	/* we don't care about local sensor, so we start at sensor 1 */
-	for (i = 1; i < 3; i++) {
-		int started = 0;
-		int fan_number = (therm_type == ADT7460 && i == 2);
-		int var = th->temps[i] - th->limits[i];
+	for (sensor = 1; sensor < 3; sensor++) {
+		int diff;
+		fan = (adt7460 && sensor == 2);
+		diff = th->temps[sensor] - th->limits[sensor];
+		if (diff > vars[fan])
+			vars[fan] = diff;
+	}
 
-		if (var > -1) {
+	/*
+	 * here we have the biggest variation for each fan (in cases where
+	 * a single fan is used for two sensors).
+	 */
+	for (fan = 0; fan < (1 + adt7460); fan++) {
+		if (vars[fan] > -1) {
 			int step = (255 - fan_speed) / 7;
 			int new_speed = 0;
 
 			/* hysteresis : change fan speed only if variation is
 			 * more than two degrees */
-			if (abs(var - th->last_var[fan_number]) < 2)
+			if (abs(vars[fan] - th->last_var[fan]) < 2)
 				continue;
 
-			started = 1;
-			new_speed = fan_speed + ((var-1)*step);
+			new_speed = fan_speed + ((vars[fan] - 1) * step);
 
 			if (new_speed < fan_speed)
 				new_speed = fan_speed;
@@ -305,29 +313,19 @@
 				new_speed = 255;
 
 			if (verbose)
-				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
-						 "(limit exceeded by %d on %s) \n",
-						new_speed, var,
-						sensor_location[fan_number+1]);
-			write_both_fan_speed(th, new_speed);
-			th->last_var[fan_number] = var;
-		} else if (var < -2) {
-			/* don't stop fan if sensor2 is cold and sensor1 is not
-			 * so cold (lastvar >= -1) */
-			if (i == 2 && lastvar < -1) {
-				if (th->last_speed[fan_number] != 0)
-					if (verbose)
-						printk(KERN_DEBUG "adt746x: Stopping "
-							"fans.\n");
-				write_both_fan_speed(th, 0);
+				printk(KERN_DEBUG "adt746x: Setting fan speed to %d "
+						 "(limit exceeded by %d)\n",
+						new_speed, vars[fan]);
+			write_fan_speed(th, new_speed, fan);
+			th->last_var[fan] = vars[fan];
+		} else if (vars[fan] < -2) {
+			if (th->last_speed[fan] != 0) {
+				if (verbose)
+					printk(KERN_DEBUG "adt746x: Stopping "
+						"fan %i.\n", fan);
+				write_fan_speed(th, 0, fan);
 			}
 		}
-
-		lastvar = var;
-
-		if (started)
-			return; /* we don't want to re-stop the fan
-				* if sensor1 is heating and sensor2 is not */
 	}
 }