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From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Linus Walleij <linus.walleij@linaro.org>,
	Kent Gibson <warthog618@gmail.com>, Alex Elder <elder@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Wolfram Sang <wsa@the-dreams.de>
Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [PATCH 16/22] gpio: reduce the functionality of validate_desc()
Date: Tue, 30 Jan 2024 13:48:22 +0100	[thread overview]
Message-ID: <20240130124828.14678-17-brgl@bgdev.pl> (raw)
In-Reply-To: <20240130124828.14678-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Checking desc->gdev->chip for NULL without holding it in place with some
serializing mechanism is pointless. Remove this check. Also don't check
desc->gdev for NULL as it can never happen.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpiolib.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index ddf7d93f8b76..0cb44578bc72 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2248,19 +2248,12 @@ static int validate_desc(const struct gpio_desc *desc, const char *func)
 {
 	if (!desc)
 		return 0;
+
 	if (IS_ERR(desc)) {
 		pr_warn("%s: invalid GPIO (errorpointer)\n", func);
 		return PTR_ERR(desc);
 	}
-	if (!desc->gdev) {
-		pr_warn("%s: invalid GPIO (no device)\n", func);
-		return -EINVAL;
-	}
-	if (!desc->gdev->chip) {
-		dev_warn(&desc->gdev->dev,
-			 "%s: backing chip is gone\n", func);
-		return 0;
-	}
+
 	return 1;
 }
 
@@ -2336,12 +2329,7 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
 
 void gpiod_free(struct gpio_desc *desc)
 {
-	/*
-	 * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip
-	 * may already be NULL but we still want to put the references.
-	 */
-	if (!desc)
-		return;
+	VALIDATE_DESC_VOID(desc);
 
 	if (!gpiod_free_commit(desc))
 		WARN_ON(1);
-- 
2.40.1


  parent reply	other threads:[~2024-01-30 12:48 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-30 12:48 [PATCH 00/22] gpio: rework locking and object life-time control Bartosz Golaszewski
2024-01-30 12:48 ` [PATCH 01/22] gpio: protect the list of GPIO devices with SRCU Bartosz Golaszewski
2024-01-31  9:34   ` kernel test robot
2024-01-31 12:45     ` Bartosz Golaszewski
2024-01-31 15:01   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 02/22] gpio: of: assign and read the hog pointer atomically Bartosz Golaszewski
2024-01-31 17:38   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 03/22] gpio: remove unused logging helpers Bartosz Golaszewski
2024-01-31 17:39   ` Linus Walleij
2024-01-31 18:08     ` Bartosz Golaszewski
2024-01-31 20:33       ` Linus Walleij
2024-01-30 12:48 ` [PATCH 04/22] gpio: provide and use gpiod_get_label() Bartosz Golaszewski
2024-01-31 19:36   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 05/22] gpio: don't set label from irq helpers Bartosz Golaszewski
2024-01-31 19:38   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 06/22] gpio: add SRCU infrastructure to struct gpio_desc Bartosz Golaszewski
2024-01-31 19:35   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 07/22] gpio: protect the descriptor label with SRCU Bartosz Golaszewski
2024-01-31 19:41   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 08/22] gpio: sysfs: use gpio_device_find() to iterate over existing devices Bartosz Golaszewski
2024-01-31 19:42   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 09/22] gpio: remove gpio_lock Bartosz Golaszewski
2024-01-31 19:51   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 10/22] gpio: reinforce desc->flags handling Bartosz Golaszewski
2024-01-31 20:01   ` Linus Walleij
2024-01-31 20:35     ` Linus Walleij
2024-02-01 18:30       ` Bartosz Golaszewski
2024-01-30 12:48 ` [PATCH 11/22] gpio: remove unneeded code from gpio_device_get_desc() Bartosz Golaszewski
2024-01-31 20:02   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 12/22] gpio: sysfs: extend the critical section for unregistering sysfs devices Bartosz Golaszewski
2024-01-31 20:06   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 13/22] gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks Bartosz Golaszewski
2024-01-31 20:09   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 14/22] gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc() Bartosz Golaszewski
2024-01-31 20:10   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 15/22] gpio: cdev: don't access gdev->chip if it's not needed Bartosz Golaszewski
2024-01-31 20:11   ` Linus Walleij
2024-01-30 12:48 ` Bartosz Golaszewski [this message]
2024-01-31 20:16   ` [PATCH 16/22] gpio: reduce the functionality of validate_desc() Linus Walleij
2024-01-31 20:19     ` Linus Walleij
2024-01-30 12:48 ` [PATCH 17/22] gpio: remove unnecessary checks from gpiod_to_chip() Bartosz Golaszewski
2024-01-30 12:48 ` [PATCH 18/22] gpio: add the can_sleep flag to struct gpio_device Bartosz Golaszewski
2024-01-31 20:17   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 19/22] gpio: add SRCU infrastructure " Bartosz Golaszewski
2024-01-30 12:48 ` [PATCH 20/22] gpio: protect the pointer to gpio_chip in gpio_device with SRCU Bartosz Golaszewski
2024-01-31  0:41   ` kernel test robot
2024-01-31  8:15     ` Bartosz Golaszewski
2024-01-31  2:20   ` kernel test robot
2024-01-31  9:02     ` Bartosz Golaszewski
2024-01-31  9:24       ` Paul E. McKenney
2024-01-31  9:28         ` Bartosz Golaszewski
2024-01-31  9:41           ` Bartosz Golaszewski
2024-01-31  9:42           ` Paul E. McKenney
2024-01-31 10:17             ` brgl
2024-01-31 11:00               ` Paul E. McKenney
2024-01-31 12:23                 ` Bartosz Golaszewski
2024-01-31 20:23   ` Linus Walleij
2024-02-01  5:03   ` Dan Carpenter
2024-02-01  7:57     ` Bartosz Golaszewski
2024-01-30 12:48 ` [PATCH 21/22] gpio: remove the RW semaphore from the GPIO device Bartosz Golaszewski
2024-01-31 20:24   ` Linus Walleij
2024-01-30 12:48 ` [PATCH 22/22] gpio: mark unsafe gpio_chip manipulators as deprecated Bartosz Golaszewski
2024-01-31 20:29   ` Linus Walleij
2024-02-01  9:14     ` Bartosz Golaszewski
2024-01-31 20:32 ` [PATCH 00/22] gpio: rework locking and object life-time control Linus Walleij
2024-02-01  8:43   ` Bartosz Golaszewski

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