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

Alek Du
2009-06-29T10:32:18Z

On Fri, 26 Jun 2009 20:15:18 +0800
Jani Nikula <ext-jani.1.nikula@nokia.com> wrote:

> 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>
> ---
> 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);
> }
>

Tested with my board, it works well. Dmitry, could you please consider
to apply it?

Tested-by: Alek Du <alek.du@intel.com>