2021-01-21 14:16:37

by Kent Gibson

Subject: [PATCH] gpiolib: cdev: clear debounce period if line set to output

When set_config changes a line from input to output debounce is
implicitly disabled, as debounce makes no sense for outputs, but the
debounce period is not being cleared and is still reported in the
line info.

So clear the debounce period when the debouncer is stopped in
edge_detector_stop().

Fixed: 65cff7047640 ("gpiolib: cdev: support setting debounce")
Signed-off-by: Kent Gibson <[email protected]>
---
drivers/gpio/gpiolib-cdev.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 12b679ca552c..3551aaf5a361 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -776,6 +776,8 @@ static void edge_detector_stop(struct line *line)
cancel_delayed_work_sync(&line->work);
WRITE_ONCE(line->sw_debounced, 0);
WRITE_ONCE(line->eflags, 0);
+ if (line->desc)
+ WRITE_ONCE(line->desc->debounce_period_us, 0);
/* do not change line->level - see comment in debounced_value() */
}

--
2.30.0

2021-01-22 22:57:40

by Linus Walleij

Subject: Re: [PATCH] gpiolib: cdev: clear debounce period if line set to output

On Thu, Jan 21, 2021 at 3:11 PM Kent Gibson <[email protected]> wrote:

> When set_config changes a line from input to output debounce is
> implicitly disabled, as debounce makes no sense for outputs, but the
> debounce period is not being cleared and is still reported in the
> line info.
>
> So clear the debounce period when the debouncer is stopped in
> edge_detector_stop().
>
> Fixed: 65cff7047640 ("gpiolib: cdev: support setting debounce")
> Signed-off-by: Kent Gibson <[email protected]>

Reviewed-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij

2021-01-28 00:01:54

by Bartosz Golaszewski

Subject: Re: [PATCH] gpiolib: cdev: clear debounce period if line set to output

On Thu, Jan 21, 2021 at 3:11 PM Kent Gibson <[email protected]> wrote:
>
> When set_config changes a line from input to output debounce is
> implicitly disabled, as debounce makes no sense for outputs, but the
> debounce period is not being cleared and is still reported in the
> line info.
>
> So clear the debounce period when the debouncer is stopped in
> edge_detector_stop().
>
> Fixed: 65cff7047640 ("gpiolib: cdev: support setting debounce")

The actual hash for this commit is 65cff7046406 - I fixed that locally.

Patch applied for fixes, thanks!

Bartosz

> Signed-off-by: Kent Gibson <[email protected]>
> ---
> drivers/gpio/gpiolib-cdev.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index 12b679ca552c..3551aaf5a361 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -776,6 +776,8 @@ static void edge_detector_stop(struct line *line)
> cancel_delayed_work_sync(&line->work);
> WRITE_ONCE(line->sw_debounced, 0);
> WRITE_ONCE(line->eflags, 0);
> + if (line->desc)
> + WRITE_ONCE(line->desc->debounce_period_us, 0);
> /* do not change line->level - see comment in debounced_value() */
> }
>
> --
> 2.30.0
>