1 files changed, 51 insertions, 21 deletions

diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
index 2d1415e16834..f967008f332e 100644
--- a/drivers/input/ff-memless.c
+++ b/drivers/input/ff-memless.c
@@ -61,7 +61,6 @@ struct ml_device {
 	struct ml_effect_state states[FF_MEMLESS_EFFECTS];
 	int gain;
 	struct timer_list timer;
-	spinlock_t timer_lock;
 	struct input_dev *dev;
 
 	int (*play_effect)(struct input_dev *dev, void *data,
@@ -222,11 +221,27 @@ static int get_compatible_type(struct ff_device *ff, int effect_type)
 }
 
 /*
+ * Only left/right direction should be used (under/over 0x8000) for
+ * forward/reverse motor direction (to keep calculation fast & simple).
+ */
+static u16 ml_calculate_direction(u16 direction, u16 force,
+				  u16 new_direction, u16 new_force)
+{
+	if (!force)
+		return new_direction;
+	if (!new_force)
+		return direction;
+	return (((u32)(direction >> 1) * force +
+		 (new_direction >> 1) * new_force) /
+		(force + new_force)) << 1;
+}
+
+/*
  * Combine two effects and apply gain.
  */
 static void ml_combine_effects(struct ff_effect *effect,
 			       struct ml_effect_state *state,
-			       unsigned int gain)
+			       int gain)
 {
 	struct ff_effect *new = state->effect;
 	unsigned int strong, weak, i;
@@ -253,8 +268,21 @@ static void ml_combine_effects(struct ff_effect *effect,
 		break;
 
 	case FF_RUMBLE:
-		strong = new->u.rumble.strong_magnitude * gain / 0xffff;
-		weak = new->u.rumble.weak_magnitude * gain / 0xffff;
+		strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
+		weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
+
+		if (effect->u.rumble.strong_magnitude + strong)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, strong);
+		else if (effect->u.rumble.weak_magnitude + weak)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.weak_magnitude,
+				new->direction, weak);
+		else
+			effect->direction = 0;
 		effect->u.rumble.strong_magnitude =
 			min(strong + effect->u.rumble.strong_magnitude,
 			    0xffffU);
@@ -269,6 +297,13 @@ static void ml_combine_effects(struct ff_effect *effect,
 		/* here we also scale it 0x7fff => 0xffff */
 		i = i * gain / 0x7fff;
 
+		if (effect->u.rumble.strong_magnitude + i)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, i);
+		else
+			effect->direction = 0;
 		effect->u.rumble.strong_magnitude =
 			min(i + effect->u.rumble.strong_magnitude, 0xffffU);
 		effect->u.rumble.weak_magnitude =
@@ -368,38 +403,38 @@ static void ml_effect_timer(unsigned long timer_data)
 {
 	struct input_dev *dev = (struct input_dev *)timer_data;
 	struct ml_device *ml = dev->ff->private;
+	unsigned long flags;
 
 	debug("timer: updating effects");
 
-	spin_lock(&ml->timer_lock);
+	spin_lock_irqsave(&dev->event_lock, flags);
 	ml_play_effects(ml);
-	spin_unlock(&ml->timer_lock);
+	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
+/*
+ * Sets requested gain for FF effects. Called with dev->event_lock held.
+ */
 static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
 {
 	struct ml_device *ml = dev->ff->private;
 	int i;
 
-	spin_lock_bh(&ml->timer_lock);
-
 	ml->gain = gain;
 
 	for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
 		__clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags);
 
 	ml_play_effects(ml);
-
-	spin_unlock_bh(&ml->timer_lock);
 }
 
+/*
+ * Start/stop specified FF effect. Called with dev->event_lock held.
+ */
 static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
 {
 	struct ml_device *ml = dev->ff->private;
 	struct ml_effect_state *state = &ml->states[effect_id];
-	unsigned long flags;
-
-	spin_lock_irqsave(&ml->timer_lock, flags);
 
 	if (value > 0) {
 		debug("initiated play");
@@ -412,8 +447,6 @@ static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
 				 msecs_to_jiffies(state->effect->replay.length);
 		state->adj_at = state->play_at;
 
-		ml_schedule_timer(ml);
-
 	} else {
 		debug("initiated stop");
 
@@ -421,11 +454,9 @@ static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
 			__set_bit(FF_EFFECT_ABORTING, &state->flags);
 		else
 			__clear_bit(FF_EFFECT_STARTED, &state->flags);
-
-		ml_play_effects(ml);
 	}
 
-	spin_unlock_irqrestore(&ml->timer_lock, flags);
+	ml_play_effects(ml);
 
 	return 0;
 }
@@ -436,7 +467,7 @@ static int ml_ff_upload(struct input_dev *dev,
 	struct ml_device *ml = dev->ff->private;
 	struct ml_effect_state *state = &ml->states[effect->id];
 
-	spin_lock_bh(&ml->timer_lock);
+	spin_lock_irq(&dev->event_lock);
 
 	if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
 		__clear_bit(FF_EFFECT_PLAYING, &state->flags);
@@ -448,7 +479,7 @@ static int ml_ff_upload(struct input_dev *dev,
 		ml_schedule_timer(ml);
 	}
 
-	spin_unlock_bh(&ml->timer_lock);
+	spin_unlock_irq(&dev->event_lock);
 
 	return 0;
 }
@@ -482,7 +513,6 @@ int input_ff_create_memless(struct input_dev *dev, void *data,
 	ml->private = data;
 	ml->play_effect = play_effect;
 	ml->gain = 0xffff;
-	spin_lock_init(&ml->timer_lock);
 	setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev);
 
 	set_bit(FF_GAIN, dev->ffbit);