[BACKPORT 5.10 PATCH] gpiolib: cdev: clear debounce period if line set to output

[Kent Gibson <warthog618@gmail.com>]

commit 03a58ea5905fdbd93ff9e52e670d802600ba38cd upstream.

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().

Fixes: 65cff7046406 ("gpiolib: cdev: support setting debounce")
Cc: stable@vger.kernel.org
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 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
@@ -756,6 +756,8 @@ static void edge_detector_stop(struct line *line)
 	cancel_delayed_work_sync(&line->work);
 	WRITE_ONCE(line->sw_debounced, 0);
 	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