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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 v3 18/24] gpio: reduce the functionality of validate_desc()
Date: Thu,  8 Feb 2024 10:59:14 +0100	[thread overview]
Message-ID: <20240208095920.8035-19-brgl@bgdev.pl> (raw)
In-Reply-To: <20240208095920.8035-1-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. We'll be protecting
gdev->chip with SRCU soon but we will provide a dedicated, automatic
class for that.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@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 6598960b29de..9be7ec470cc0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2257,19 +2257,12 @@ 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;
 }
 
@@ -2345,12 +2338,7 @@ 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:[~2024-02-08  9:59 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-08  9:58 [PATCH v3 00/24] gpio: rework locking and object life-time control Bartosz Golaszewski
2024-02-08  9:58 ` [PATCH v3 01/24] gpio: protect the list of GPIO devices with SRCU Bartosz Golaszewski
2024-02-10 11:00   ` Hillf Danton
2024-02-10 11:07     ` Bartosz Golaszewski
2024-02-08  9:58 ` [PATCH v3 02/24] gpio: of: assign and read the hog pointer atomically Bartosz Golaszewski
2024-02-08  9:58 ` [PATCH v3 03/24] gpio: remove unused logging helpers Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 04/24] gpio: provide and use gpiod_get_label() Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 05/24] gpio: don't set label from irq helpers Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 06/24] gpio: add SRCU infrastructure to struct gpio_desc Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 07/24] gpio: protect the descriptor label with SRCU Bartosz Golaszewski
2024-02-12 14:56   ` kernel test robot
2024-02-13 21:16   ` Mark Brown
2024-02-13 22:07     ` Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 08/24] gpio: sysfs: use gpio_device_find() to iterate over existing devices Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 09/24] gpio: remove gpio_lock Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 10/24] gpio: reinforce desc->flags handling Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 11/24] gpio: remove unneeded code from gpio_device_get_desc() Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 12/24] gpio: sysfs: extend the critical section for unregistering sysfs devices Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 13/24] gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 14/24] gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc() Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 15/24] gpio: cdev: don't access gdev->chip if it's not needed Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 16/24] gpio: sysfs: " Bartosz Golaszewski
2024-02-08 12:20   ` Linus Walleij
2024-02-08  9:59 ` [PATCH v3 17/24] gpio: don't dereference gdev->chip in gpiochip_setup_dev() Bartosz Golaszewski
2024-02-08 12:21   ` Linus Walleij
2024-02-08  9:59 ` Bartosz Golaszewski [this message]
2024-02-08  9:59 ` [PATCH v3 19/24] gpio: remove unnecessary checks from gpiod_to_chip() Bartosz Golaszewski
2024-02-08 17:39   ` Andy Shevchenko
2024-02-08 19:17     ` Bartosz Golaszewski
2024-02-08 19:24       ` Andy Shevchenko
2024-02-08 19:34         ` Bartosz Golaszewski
2024-02-09 13:59           ` Andy Shevchenko
2024-02-08  9:59 ` [PATCH v3 20/24] gpio: add the can_sleep flag to struct gpio_device Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 21/24] gpio: add SRCU infrastructure " Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 22/24] gpio: protect the pointer to gpio_chip in gpio_device with SRCU Bartosz Golaszewski
2024-02-12 15:09   ` kernel test robot
2024-02-12 16:56     ` Bartosz Golaszewski
2024-02-12 21:20     ` Bartosz Golaszewski
2024-02-13  8:10       ` Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 23/24] gpio: remove the RW semaphore from the GPIO device Bartosz Golaszewski
2024-02-10  5:37   ` Kent Gibson
2024-02-12  9:53     ` Bartosz Golaszewski
2024-02-12  9:57       ` Kent Gibson
2024-02-12  9:59         ` Bartosz Golaszewski
2024-02-08  9:59 ` [PATCH v3 24/24] gpio: mark unsafe gpio_chip manipulators as deprecated Bartosz Golaszewski
2024-02-08 17:43 ` [PATCH v3 00/24] gpio: rework locking and object life-time control Andy Shevchenko
2024-02-12 10:07 ` Bartosz Golaszewski
     [not found] ` <CGME20240213120518eucas1p2d514aac6e6d1e29bbae05f32db6724db@eucas1p2.samsung.com>
2024-02-13 12:05   ` Marek Szyprowski
2024-02-13 12:08     ` Bartosz Golaszewski

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