drm/nouveau/therm: better transitions and debug logging

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Martin Peres <martin.peres@labri.fr>

drivers/gpu/drm/nouveau/core/include/subdev/therm.h

@@ -4,11 +4,10 @@
 #include <core/device.h>
 #include <core/subdev.h>
 
-enum nouveau_therm_fan_mode {
-	FAN_CONTROL_NONE = 0,
-	FAN_CONTROL_MANUAL = 1,
-	FAN_CONTROL_AUTO = 2,
-	FAN_CONTROL_NR,
+enum nouveau_therm_mode {
+	NOUVEAU_THERM_CTRL_NONE = 0,
+	NOUVEAU_THERM_CTRL_MANUAL = 1,
+	NOUVEAU_THERM_CTRL_AUTO = 2,
 };
 
 enum nouveau_therm_attr_type {

drivers/gpu/drm/nouveau/core/subdev/therm/base.c

@@ -93,24 +93,27 @@ nouveau_therm_update(struct nouveau_therm *therm, int mode)
 	priv->mode = mode;
 
 	switch (mode) {
-	case FAN_CONTROL_MANUAL:
-		duty = priv->fan->percent;
+	case NOUVEAU_THERM_CTRL_MANUAL:
+		duty = nouveau_therm_fan_get(therm);
+		if (duty < 0)
+			duty = 100;
 		break;
-	case FAN_CONTROL_AUTO:
+	case NOUVEAU_THERM_CTRL_AUTO:
 		if (priv->fan->bios.nr_fan_trip)
 			duty = nouveau_therm_update_trip(therm);
 		else
 			duty = nouveau_therm_update_linear(therm);
 		break;
-	case FAN_CONTROL_NONE:
+	case NOUVEAU_THERM_CTRL_NONE:
 	default:
 		goto done;
 	}
 
-	nouveau_therm_fan_set(therm, (mode != FAN_CONTROL_AUTO), duty);
+	nv_debug(therm, "FAN target request: %d%%\n", duty);
+	nouveau_therm_fan_set(therm, (mode != NOUVEAU_THERM_CTRL_AUTO), duty);
 
 done:
-	if (list_empty(&priv->alarm.head) && (mode == FAN_CONTROL_AUTO))
+	if (list_empty(&priv->alarm.head) && (mode == NOUVEAU_THERM_CTRL_AUTO))
 		ptimer->alarm(ptimer, 1000000000ULL, &priv->alarm);
 	spin_unlock_irqrestore(&priv->lock, flags);
 }
@@ -127,28 +130,22 @@ int
 nouveau_therm_mode(struct nouveau_therm *therm, int mode)
 {
 	struct nouveau_therm_priv *priv = (void *)therm;
-
-	if (priv->mode == mode)
-		return 0;
+	struct nouveau_device *device = nv_device(therm);
+	static const char *name[] = {
+		"disabled",
+		"manual",
+		"automatic"
+	};
 
 	/* The default PDAEMON ucode interferes with fan management */
-	if (nv_device(therm)->card_type >= NV_C0)
+	if ((mode >= ARRAY_SIZE(name)) ||
+	    (mode != NOUVEAU_THERM_CTRL_NONE && device->card_type >= NV_C0))
 		return -EINVAL;
 
-	switch (mode) {
-	case FAN_CONTROL_NONE:
-		nv_info(therm, "switch to no-control mode\n");
-		break;
-	case FAN_CONTROL_MANUAL:
-		nv_info(therm, "switch to manual mode\n");
-		break;
-	case FAN_CONTROL_AUTO:
-		nv_info(therm, "switch to automatic mode\n");
-		break;
-	default:
-		return -EINVAL;
-	}
+	if (priv->mode == mode)
+		return 0;
 
+	nv_info(therm, "Thermal management: %s\n", name[mode]);
 	nouveau_therm_update(therm, mode);
 	return 0;
 }
@@ -258,9 +255,8 @@ _nouveau_therm_init(struct nouveau_object *object)
 	if (ret)
 		return ret;
 
-	if (priv->fan->percent >= 0)
-		therm->fan_set(therm, priv->fan->percent);
-
+	if (priv->suspend >= 0)
+		nouveau_therm_mode(therm, priv->mode);
 	priv->sensor.program_alarms(therm);
 	return 0;
 }
@@ -271,7 +267,10 @@ _nouveau_therm_fini(struct nouveau_object *object, bool suspend)
 	struct nouveau_therm *therm = (void *)object;
 	struct nouveau_therm_priv *priv = (void *)therm;
 
-	priv->fan->percent = therm->fan_get(therm);
+	if (suspend) {
+		priv->suspend = priv->mode;
+		priv->mode = NOUVEAU_THERM_CTRL_NONE;
+	}
 
 	return nouveau_subdev_fini(&therm->base, suspend);
 }
@@ -299,6 +298,7 @@ nouveau_therm_create_(struct nouveau_object *parent,
 	priv->base.fan_sense = nouveau_therm_fan_sense;
 	priv->base.attr_get = nouveau_therm_attr_get;
 	priv->base.attr_set = nouveau_therm_attr_set;
+	priv->mode = priv->suspend = -1; /* undefined */
 	return 0;
 }
 
@@ -308,6 +308,8 @@ nouveau_therm_preinit(struct nouveau_therm *therm)
 	nouveau_therm_ic_ctor(therm);
 	nouveau_therm_sensor_ctor(therm);
 	nouveau_therm_fan_ctor(therm);
+
+	nouveau_therm_mode(therm, NOUVEAU_THERM_CTRL_NONE);
 	return 0;
 }
 

drivers/gpu/drm/nouveau/core/subdev/therm/fan.c

@@ -47,10 +47,17 @@ nouveau_fan_update(struct nouveau_fan *fan, bool immediate, int target)
 		target = fan->percent;
 	target = max_t(u8, target, fan->bios.min_duty);
 	target = min_t(u8, target, fan->bios.max_duty);
-	fan->percent = target;
+	if (fan->percent != target) {
+		nv_debug(therm, "FAN target: %d\n", target);
+		fan->percent = target;
+	}
 
-	/* smooth out the fanspeed increase/decrease */
+	/* check that we're not already at the target duty cycle */
 	duty = fan->get(therm);
+	if (duty == target)
+		goto done;
+
+	/* smooth out the fanspeed increase/decrease */
 	if (!immediate && duty >= 0) {
 		/* the constant "3" is a rough approximation taken from
 		 * nvidia's behaviour.
@@ -64,6 +71,7 @@ nouveau_fan_update(struct nouveau_fan *fan, bool immediate, int target)
 		duty = target;
 	}
 
+	nv_debug(therm, "FAN update: %d\n", duty);
 	ret = fan->set(therm, duty);
 	if (ret)
 		goto done;
@@ -161,7 +169,7 @@ nouveau_therm_fan_user_set(struct nouveau_therm *therm, int percent)
 {
 	struct nouveau_therm_priv *priv = (void *)therm;
 
-	if (priv->mode != FAN_CONTROL_MANUAL)
+	if (priv->mode != NOUVEAU_THERM_CTRL_MANUAL)
 		return -EINVAL;
 
 	return nouveau_therm_fan_set(therm, true, percent);

drivers/gpu/drm/nouveau/core/subdev/therm/priv.h

@@ -76,6 +76,7 @@ struct nouveau_therm_priv {
 	spinlock_t lock;
 	struct nouveau_therm_trip_point *last_trip;
 	int mode;
+	int suspend;
 
 	/* bios */
 	struct nvbios_therm_sensor bios_sensor;

drivers/gpu/drm/nouveau/core/subdev/therm/temp.c

@@ -108,7 +108,7 @@ void nouveau_therm_sensor_event(struct nouveau_therm *therm,
 	switch (thrs) {
 	case NOUVEAU_THERM_THRS_FANBOOST:
 		nouveau_therm_fan_set(therm, true, 100);
-		nouveau_therm_mode(therm, FAN_CONTROL_AUTO);
+		nouveau_therm_mode(therm, NOUVEAU_THERM_CTRL_AUTO);
 		break;
 	case NOUVEAU_THERM_THRS_DOWNCLOCK:
 		if (priv->emergency.downclock)