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

Alek Du
2009-06-25T16:28:52Z

On Fri, 26 Jun 2009 00:09:14 +0800
Phil Carmody <ext-phil.2.carmody@nokia.com> wrote:

> If you stopped calling the delay after the first transition "debouncing
> time" and simply called it a "delay" you might more easily see that it
> does *no* debouncing at all. Imagine putting noise on the line
> constantly - the original code's timer would never expire. Your timer
> will expire after a delay, and while the line is still toggling
> frantically - you've not debounced.

I don't know if it is really meaningful if you want to handle such pool signal...
Ok, if you want to handle this ultimate case, will this patch work?

BUG_ON(irq != gpio_to_irq(button->gpio));

+ cancel_delayed_work_sync(&bdata->work);
delay = button->debounce_interval ?
msecs_to_jiffies(button->debounce_interval) : 0;
schedule_delayed_work(&bdata->work, delay);

Alek
> Please investigate the meaning and implications of "debouncing" before
> claiming your code does it.
>
> Phil
>