[PATCH v3 05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev_open()

Tzung-Bi Shih posted 11 patches 1 month, 2 weeks ago
[PATCH v3 05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev_open()
Posted by Tzung-Bi Shih 1 month, 2 weeks ago
It's harmless even if: chrdev_open() and cdev_device_del() run at the
same time, and gpio_chrdev_open() gets called after the underlying GPIO
chip has gone.  The subsequent file operations check the availability
of struct gpio_chip anyway.

Don't check struct gpio_chip in gpio_chrdev_open().

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
v3:
- No changes.

v2: https://lore.kernel.org/all/20260203061059.975605-6-tzungbi@kernel.org
- No changes.

v1: https://lore.kernel.org/all/20260116081036.352286-11-tzungbi@kernel.org

 drivers/gpio/gpiolib-cdev.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index b028198adba8..2e3484a89a3b 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2689,12 +2689,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	struct gpio_chardev_data *cdev;
 	int ret = -ENOMEM;
 
-	guard(srcu)(&gdev->srcu);
-
-	/* Fail on open if the backing gpiochip is gone */
-	if (!rcu_access_pointer(gdev->chip))
-		return -ENODEV;
-
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
 		return -ENOMEM;
-- 
2.53.0.310.g728cabbaf7-goog
Re: [PATCH v3 05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev_open()
Posted by Linus Walleij 1 month, 1 week ago
On Fri, Feb 13, 2026 at 10:31 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:

> It's harmless even if: chrdev_open() and cdev_device_del() run at the
> same time, and gpio_chrdev_open() gets called after the underlying GPIO
> chip has gone.  The subsequent file operations check the availability
> of struct gpio_chip anyway.
>
> Don't check struct gpio_chip in gpio_chrdev_open().
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij