Input: gpio-keys - avoid possibility of sleeping in timer function

The gpio_get_value function may sleep, so it should not be called in a
timer function. Move gpio_get_value calls to workqueue.

Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/gpio_keys.c

@@ -22,22 +22,26 @@
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/gpio_keys.h>
+#include <linux/workqueue.h>
 
 #include <asm/gpio.h>
 
 struct gpio_button_data {
 	struct gpio_keys_button *button;
 	struct input_dev *input;
 	struct timer_list timer;
+	struct work_struct work;
 };
 
 struct gpio_keys_drvdata {
 	struct input_dev *input;
 	struct gpio_button_data data[0];
 };
 
-static void gpio_keys_report_event(struct gpio_button_data *bdata)
+static void gpio_keys_report_event(struct work_struct *work)
 {
+	struct gpio_button_data *bdata =
+		container_of(work, struct gpio_button_data, work);
 	struct gpio_keys_button *button = bdata->button;
 	struct input_dev *input = bdata->input;
 	unsigned int type = button->type ?: EV_KEY;
@@ -47,11 +51,11 @@ static void gpio_keys_report_event(struct gpio_button_data *bdata)
 	input_sync(input);
 }
 
-static void gpio_check_button(unsigned long _data)
+static void gpio_keys_timer(unsigned long _data)
 {
 	struct gpio_button_data *data = (struct gpio_button_data *)_data;
 
-	gpio_keys_report_event(data);
+	schedule_work(&data->work);
 }
 
 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
@@ -65,7 +69,7 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
 		mod_timer(&bdata->timer,
 			jiffies + msecs_to_jiffies(button->debounce_interval));
 	else
-		gpio_keys_report_event(bdata);
+		schedule_work(&bdata->work);
 
 	return IRQ_HANDLED;
 }
@@ -113,7 +117,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
 		bdata->input = input;
 		bdata->button = button;
 		setup_timer(&bdata->timer,
-			    gpio_check_button, (unsigned long)bdata);
+			    gpio_keys_timer, (unsigned long)bdata);
+		INIT_WORK(&bdata->work, gpio_keys_report_event);
 
 		error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
 		if (error < 0) {
@@ -174,6 +179,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
 		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
 		if (pdata->buttons[i].debounce_interval)
 			del_timer_sync(&ddata->data[i].timer);
+		cancel_work_sync(&ddata->data[i].work);
 		gpio_free(pdata->buttons[i].gpio);
 	}
 
@@ -199,6 +205,7 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
 		free_irq(irq, &ddata->data[i]);
 		if (pdata->buttons[i].debounce_interval)
 			del_timer_sync(&ddata->data[i].timer);
+		cancel_work_sync(&ddata->data[i].work);
 		gpio_free(pdata->buttons[i].gpio);
 	}