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Re: Sensors in adt746x



On 28 Oct 2004 at 18h10, Georg C. Kaindl wrote:

Hi, 

> But when watching the behaviour of the fan speed stepping code I noticed that 
> it happens quite often that when reducing the fan speed it will get set to 
> values < fan_speed because of (var > -2). I don't know wether this is 
> intended but I think it is a indeed a good idea to slightly expand the range 
> between starting the fan and overriding the value, starting out really slow. 
> However it would be good to add another check for a reasonably high new_speed 
> because by changing the fan_speed parameter one could reach fan speeds as low 
> as 1. Maybe 20 is a good lower bound value...
> additionally, it doesn't look like the special case of overriding the 
> specified fan speed is needed anymore because at var == 8 and latest at var 
> ==9 (because of hysteresis) we reach 255 anyways, but var == 9 also is the 
> first case where we would override...

Thanks for your feedback. You're right, I missed these two points... Here's
an updated patch that should behave more logically (ie, starting when temp
== lim and stopping when temp < lim - 2), and removing the override case that
isn't needed anymore.

I may not be able to follow up on this until monday evening, but will do asap.

-- 
Colin
  http://dudusdl.sf.net/ : a free Puzzle Bubble clone
--- a/drivers/macintosh/therm_adt746x.c	2004-10-28 16:02:13.363979632 +0200
+++ b/drivers/macintosh/therm_adt746x.c	2004-10-28 22:10:19.433920744 +0200
@@ -61,8 +61,8 @@
 		 "by N degrees.");
 
 MODULE_PARM(fan_speed,"i");
-MODULE_PARM_DESC(fan_speed,"Specify fan speed (0-255) when lim < temp < lim+8 "
-		 "(default 128)");
+MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
+		 "(default 64)");
 
 struct thermostat {
 	struct i2c_client	clt;
@@ -71,7 +71,7 @@
 	u8			initial_limits[3];
 	u8			limits[3];
 	int			last_speed[2];
-	int			overriding[2];
+	int			last_var[2];
 };
 
 static enum {ADT7460, ADT7467} therm_type;
@@ -80,7 +80,7 @@
 static struct thermostat* thermostat;
 static struct task_struct *thread_therm = NULL;
 
-static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
+static int attach_one_thermostat(struct i2c_adapter *adapter, int addr, 
 				 int busno);
 
 static void write_both_fan_speed(struct thermostat *th, int speed);
@@ -151,7 +151,7 @@
 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
 			 "%d, %d, %d to %d, %d, %d\n",
 		th->limits[0], th->limits[1], th->limits[2],
-		th->initial_limits[0], th->initial_limits[1],
+		th->initial_limits[0], th->initial_limits[1], 
 		th->initial_limits[2]);
 	
 	for (i = 0; i < 3; i++)
@@ -211,10 +211,10 @@
 	
 	if (th->last_speed[fan] != speed) {
 		if (speed == -1)
-			printk(KERN_INFO "adt746x: Setting speed to automatic "
+			printk(KERN_DEBUG "adt746x: Setting speed to automatic "
 				"for %s fan.\n", fan?"GPU":"CPU");
 		else
-			printk(KERN_INFO "adt746x: Setting speed to %d "
+			printk(KERN_DEBUG "adt746x: Setting speed to %d "
 				"for %s fan.\n", speed, fan?"GPU":"CPU");
 	} else
 		return;
@@ -226,10 +226,10 @@
 	} else {
 		/* back to automatic */
 		if(therm_type == ADT7460) {
-			manual = read_reg(th,
+			manual = read_reg(th, 
 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
 
-			write_reg(th,
+			write_reg(th, 
 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
 		} else {
 			manual = read_reg(th, MANUAL_MODE[fan]);
@@ -243,7 +243,7 @@
 static void read_sensors(struct thermostat *th)
 {
 	int i = 0;
-
+	
 	for (i = 0; i < 3; i++)
 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
 }
@@ -272,49 +272,49 @@
 {
 	int lastvar = 0; /* last variation, for iBook */
 	int i = 0;
-
+	
 	/* 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];
-		if (var > 8) {
-			if (th->overriding[fan_number] == 0)
-				printk(KERN_INFO "adt746x: Limit exceeded by "
-					"%d, overriding specified fan speed "
-					"for %s.\n", var,
-					fan_number?"GPU":"CPU");
-
-			th->overriding[fan_number] = 1;
-			write_fan_speed(th, 255, fan_number);
-			started = 1;
-		} else if ((!th->overriding[fan_number] || var < 6) && var > 0) {
-			if (th->overriding[fan_number] == 1)
-				printk(KERN_INFO "adt746x: Limit exceeded by "
-					"%d, setting speed to specified "
-					"for %s.\n", var,
-					fan_number?"GPU":"CPU");
-
-			th->overriding[fan_number] = 0;
-			write_fan_speed(th, fan_speed, fan_number);
+		
+		if (var > -1) {
+			int step = (255 - fan_speed) / 7;
+			int new_speed = 0;
+
+			/* hysteresis : change fan speed only if variation is
+			 * more than two degrees */
+			if (var > 6 || abs(var - th->last_var[fan_number]) < 2)
+				continue;
+			
 			started = 1;
-		} else if (var < -1) {
-			/* don't stop iBook fan if GPU is cold and CPU is not
+			new_speed = fan_speed + ((var-1)*step);
+			if (new_speed < fan_speed)
+				new_speed = fan_speed;
+
+			printk(KERN_DEBUG "adt746x: setting fans speed to %d "
+					 "(limit exceeded by %d on %s) \n",
+					new_speed, var,
+					fan_number?"GPU/pwr":"CPU");
+			write_both_fan_speed(th, new_speed);
+			th->last_var[fan_number] = var;
+		} else if (var < -2) {
+			/* don't stop fan if GPU/power is cold and CPU is not
 			 * so cold (lastvar >= -1) */
-			if (therm_type == ADT7460 || lastvar < -1 || i == 1) {
+			if (i == 2 && lastvar < -1) {
 				if (th->last_speed[fan_number] != 0)
-					printk(KERN_INFO "adt746x: Stopping %s "
-						"fan.\n",
-						fan_number?"GPU":"CPU");
-				write_fan_speed(th, 0, fan_number);
+					printk(KERN_DEBUG "adt746x: Stopping "
+						"fans.\n");
+				write_both_fan_speed(th, 0);
 			}
 		}
 
 		lastvar = var;
 
-		if (started && therm_type == ADT7467)
+		if (started)
 			return; /* we don't want to re-stop the fan
-				* if CPU is heating and GPU is not */
+				* if CPU is heating and GPU/power is not */
 	}
 }
 
@@ -327,7 +327,7 @@
 			refrigerator(PF_FREEZE);
 
 		msleep_interruptible(2000);
-
+		 
 #ifndef DEBUG
 		if (fan_speed != -1)
 			read_sensors(th);
@@ -357,7 +357,7 @@
 		th->limits[i] = default_limits_local[i] + limit_adjust;
 }
 
-static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
+static int attach_one_thermostat(struct i2c_adapter *adapter, int addr, 
 				 int busno)
 {
 	struct thermostat* th;
@@ -391,7 +391,7 @@
 
 	/* force manual control to start the fan quieter */
 	if (fan_speed == -1)
-		fan_speed=128;
+		fan_speed=64;
 	
 	if(therm_type == ADT7460) {
 		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
@@ -407,8 +407,8 @@
 	
 	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
 			 " to %d, %d, %d\n",
-			 th->initial_limits[0], th->initial_limits[1],
-			 th->initial_limits[2], th->limits[0], th->limits[1],
+			 th->initial_limits[0], th->initial_limits[1], 
+			 th->initial_limits[2], th->limits[0], th->limits[1], 
 			 th->limits[2]);
 
 	thermostat = th;
@@ -424,7 +424,9 @@
 	/* be sure to really write fan speed the first time */
 	th->last_speed[0] = -2;
 	th->last_speed[1] = -2;
-	
+	th->last_var[0] = -80;
+	th->last_var[1] = -80;
+
 	if (fan_speed != -1) {
 		/* manual mode, stop fans */
 		write_both_fan_speed(th, 0);
@@ -585,9 +587,9 @@
 		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
 		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
 		device_remove_file(&of_dev->dev, &dev_attr_cpu_fan_speed);
-
+		
 		if(therm_type == ADT7460)
-			device_remove_file(&of_dev->dev,
+			device_remove_file(&of_dev->dev, 
 					   &dev_attr_gpu_fan_speed);
 
 		of_device_unregister(of_dev);

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