linux-kernel - [PATCH 2/2] input: gpio-keys: avoid possibility of sleeping in timer function

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Message-Id: <7dbf3c1888fe61729b6c9e399971012611122a28.1246015395.git.ext-jani.1.nikula@nokia.com>
Date:	Fri, 26 Jun 2009 15:15:18 +0300
From:	Jani Nikula <ext-jani.1.nikula@...ia.com>
To:	alek.du@...el.com
Cc:	dmitry.torokhov@...il.com, linux-kernel@...r.kernel.org,
	linux-input@...r.kernel.org, soni.trilok@...il.com,
	ben-linux@...ff.org, ext-phil.2.carmody@...ia.com,
	ext-jani.1.nikula@...ia.com
Subject: [PATCH 2/2] 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@...ia.com>
---
 drivers/input/keyboard/gpio_keys.c |   17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 9767213..efed0c9 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -22,6 +22,7 @@
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/gpio_keys.h>
+#include <linux/workqueue.h>
 
 #include <asm/gpio.h>
 
@@ -29,6 +30,7 @@ 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 {
@@ -36,8 +38,10 @@ struct gpio_keys_drvdata {
 	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);
 	}
 
-- 
1.6.3.2

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