Input: synaptics_i2c - switch to using __cancel_delayed_work()

cancel_delayed_work() may spin and therefore should not be used in
interrupt contexts.
Acked-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/synaptics_i2c.c

@@ -203,7 +203,7 @@ MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
  * and the irq configuration should be set to Falling Edge Trigger
  */
 /* Control IRQ / Polling option */
-static int polling_req;
+static bool polling_req;
 module_param(polling_req, bool, 0444);
 MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
 
@@ -217,6 +217,7 @@ struct synaptics_i2c {
 	struct i2c_client	*client;
 	struct input_dev	*input;
 	struct delayed_work	dwork;
+	spinlock_t		lock;
 	int			no_data_count;
 	int			no_decel_param;
 	int			reduce_report_param;
@@ -366,17 +367,28 @@ static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
 	return xy_delta || gesture;
 }
 
-static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
+static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
+					  unsigned long delay)
 {
-	struct synaptics_i2c *touch = dev_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&touch->lock, flags);
 
 	/*
-	 * We want to have the work run immediately but it might have
-	 * already been scheduled with a delay, that's why we have to
-	 * cancel it first.
+	 * If work is already scheduled then subsequent schedules will not
+	 * change the scheduled time that's why we have to cancel it first.
 	 */
-	cancel_delayed_work(&touch->dwork);
-	schedule_delayed_work(&touch->dwork, 0);
+	__cancel_delayed_work(&touch->dwork);
+	schedule_delayed_work(&touch->dwork, delay);
+
+	spin_unlock_irqrestore(&touch->lock, flags);
+}
+
+static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
+{
+	struct synaptics_i2c *touch = dev_id;
+
+	synaptics_i2c_reschedule_work(touch, 0);
 
 	return IRQ_HANDLED;
 }
@@ -452,7 +464,7 @@ static void synaptics_i2c_work_handler(struct work_struct *work)
 	 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
 	 * if error is detected, we try to reset and reconfigure the touchpad.
 	 */
-	schedule_delayed_work(&touch->dwork, delay);
+	synaptics_i2c_reschedule_work(touch, delay);
 }
 
 static int synaptics_i2c_open(struct input_dev *input)
@@ -465,8 +477,8 @@ static int synaptics_i2c_open(struct input_dev *input)
 		return ret;
 
 	if (polling_req)
-		schedule_delayed_work(&touch->dwork,
-				       msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
+		synaptics_i2c_reschedule_work(touch,
+				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
 
 	return 0;
 }
@@ -521,6 +533,7 @@ struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
 	touch->scan_rate_param = scan_rate;
 	set_scan_rate(touch, scan_rate);
 	INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
+	spin_lock_init(&touch->lock);
 
 	return touch;
 }
@@ -535,14 +548,12 @@ static int __devinit synaptics_i2c_probe(struct i2c_client *client,
 	if (!touch)
 		return -ENOMEM;
 
-	i2c_set_clientdata(client, touch);
-
 	ret = synaptics_i2c_reset_config(client);
 	if (ret)
 		goto err_mem_free;
 
 	if (client->irq < 1)
-		polling_req = 1;
+		polling_req = true;
 
 	touch->input = input_allocate_device();
 	if (!touch->input) {
@@ -563,7 +574,7 @@ static int __devinit synaptics_i2c_probe(struct i2c_client *client,
 			dev_warn(&touch->client->dev,
 				  "IRQ request failed: %d, "
 				  "falling back to polling\n", ret);
-			polling_req = 1;
+			polling_req = true;
 			synaptics_i2c_reg_set(touch->client,
 					      INTERRUPT_EN_REG, 0);
 		}
@@ -580,12 +591,14 @@ static int __devinit synaptics_i2c_probe(struct i2c_client *client,
 			 "Input device register failed: %d\n", ret);
 		goto err_input_free;
 	}
+
+	i2c_set_clientdata(client, touch);
+
 	return 0;
 
 err_input_free:
 	input_free_device(touch->input);
 err_mem_free:
-	i2c_set_clientdata(client, NULL);
 	kfree(touch);
 
 	return ret;
@@ -596,7 +609,7 @@ static int __devexit synaptics_i2c_remove(struct i2c_client *client)
 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
 
 	if (!polling_req)
-		free_irq(touch->client->irq, touch);
+		free_irq(client->irq, touch);
 
 	input_unregister_device(touch->input);
 	i2c_set_clientdata(client, NULL);
@@ -627,8 +640,8 @@ static int synaptics_i2c_resume(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	schedule_delayed_work(&touch->dwork,
-			       msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
+	synaptics_i2c_reschedule_work(touch,
+				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
 
 	return 0;
 }