Re: [PATCH]input: Change timer function to workqueue for gpio_keys driver

[Jani Nikula]

On Fri, Jun 12, 2009 at 8:40 PM, Trilok Soni<soni.trilok@xxxxxxxxx> wrote:
>> Âstatic irqreturn_t gpio_keys_isr(int irq, void *dev_id)
>> Â{
>> Â Â Â Âstruct gpio_button_data *bdata = dev_id;
>> @@ -62,10 +61,10 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
>> Â Â Â ÂBUG_ON(irq != gpio_to_irq(button->gpio));
>>
>> Â Â Â Âif (button->debounce_interval)
>> - Â Â Â Â Â Â Â mod_timer(&bdata->timer,
>> - Â Â Â Â Â Â Â Â Â Â Â jiffies + msecs_to_jiffies(button->debounce_interval));
>> + Â Â Â Â Â Â Â schedule_delayed_work(&bdata->work,
>> + Â Â Â Â Â Â Â Â Â Â Â msecs_to_jiffies(button->debounce_interval));
>> Â Â Â Âelse
>> - Â Â Â Â Â Â Â gpio_keys_report_event(bdata);
>> + Â Â Â Â Â Â Â schedule_work(&bdata->work.work);
>>
>> Â Â Â Âreturn IRQ_HANDLED;
>> Â}

Correct me if I'm wrong, but as far as I can tell,
schedule_delayed_work doesn't modify the timer if the work was already
pending. The result is not the same as with the timer. This breaks the
debouncing.

It looks like a slightly modified version of this patch has already
been committed [1], but it has the same problem.

[1] 0b346838c5862bfe911432956a106d602535d030 Input: gpio-keys - change
timer to workqueue


BR,
Jani.
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