[PATCH v3 3/5] gpiolib: clear debounce period before the "requested" flag

[Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>]

The debounce_period_us field is protected by the GPIOD_FLAG_REQUESTED
flag, so it should be cleared before the flag, else it could potentially
race with a new request.

Suggested-by: Kent Gibson <warthog618@gmail.com>
Closes: https://lore.kernel.org/all/20261105042905.GB8436@rigel/
Fixes: 81625f362497 ("gpio: cdev: go back to storing debounce period in the GPIO descriptor")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/gpio/gpiolib.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 1285a993a1ceeff719142ad019451d2e9af6a520..ce8531a8e95dd3bdff7ca32f4e486b329a19afaf 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2699,6 +2699,10 @@ void gpiod_free_commit(struct gpio_desc *desc)
 		if (guard.gc->free)
 			guard.gc->free(guard.gc, gpiod_hwgpio(desc));
 
+#ifdef CONFIG_GPIO_CDEV
+		WRITE_ONCE(desc->debounce_period_us, 0);
+#endif
+
 		clear_bit(GPIOD_FLAG_ACTIVE_LOW, &flags);
 		clear_bit(GPIOD_FLAG_REQUESTED, &flags);
 		clear_bit(GPIOD_FLAG_OPEN_DRAIN, &flags);
@@ -2716,9 +2720,6 @@ void gpiod_free_commit(struct gpio_desc *desc)
 #endif
 		desc_set_label(desc, NULL);
 		WRITE_ONCE(desc->flags, flags);
-#ifdef CONFIG_GPIO_CDEV
-		WRITE_ONCE(desc->debounce_period_us, 0);
-#endif
 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED);
 	}
 }

-- 
2.47.3