From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: 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>,
Wolfram Sang <wsa@the-dreams.de>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: Re: [PATCH v2 17/23] gpio: reduce the functionality of validate_desc()
Date: Mon, 5 Feb 2024 14:22:03 +0200 [thread overview]
Message-ID: <ZcDS60dB39y-B6WR@smile.fi.intel.com> (raw)
In-Reply-To: <20240205093418.39755-18-brgl@bgdev.pl>
On Mon, Feb 05, 2024 at 10:34:12AM +0100, Bartosz Golaszewski wrote:
> 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.
...
> 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);
IIRC we (used to) have two cases like this (you added one in some code like
last year).
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2024-02-05 13:47 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-05 9:33 [PATCH v2 00/23] gpio: rework locking and object life-time control Bartosz Golaszewski
2024-02-05 9:33 ` [PATCH v2 01/23] gpio: protect the list of GPIO devices with SRCU Bartosz Golaszewski
2024-02-05 9:33 ` [PATCH v2 02/23] gpio: of: assign and read the hog pointer atomically Bartosz Golaszewski
2024-02-05 9:33 ` [PATCH v2 03/23] gpio: remove unused logging helpers Bartosz Golaszewski
2024-02-05 9:33 ` [PATCH v2 04/23] gpio: provide and use gpiod_get_label() Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 05/23] gpio: don't set label from irq helpers Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 06/23] gpio: add SRCU infrastructure to struct gpio_desc Bartosz Golaszewski
2024-02-05 12:16 ` Andy Shevchenko
2024-02-05 13:54 ` Bartosz Golaszewski
2024-02-05 13:57 ` Andy Shevchenko
2024-02-05 14:04 ` Bartosz Golaszewski
2024-02-05 14:06 ` Andy Shevchenko
2024-02-05 14:07 ` Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 07/23] gpio: protect the descriptor label with SRCU Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 08/23] gpio: sysfs: use gpio_device_find() to iterate over existing devices Bartosz Golaszewski
2024-02-05 12:18 ` Andy Shevchenko
2024-02-05 13:19 ` Bartosz Golaszewski
2024-02-05 13:38 ` Andy Shevchenko
2024-02-05 13:39 ` Bartosz Golaszewski
2024-02-05 13:47 ` Andy Shevchenko
2024-02-05 13:50 ` Bartosz Golaszewski
2024-02-05 13:58 ` Andy Shevchenko
2024-02-05 14:04 ` Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 09/23] gpio: remove gpio_lock Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 10/23] gpio: reinforce desc->flags handling Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 11/23] gpio: remove unneeded code from gpio_device_get_desc() Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 12/23] gpio: sysfs: extend the critical section for unregistering sysfs devices Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 13/23] gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 14/23] gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc() Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 15/23] gpio: cdev: don't access gdev->chip if it's not needed Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 16/23] gpio: don't dereference gdev->chip in gpiochip_setup_dev() Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 17/23] gpio: reduce the functionality of validate_desc() Bartosz Golaszewski
2024-02-05 12:22 ` Andy Shevchenko [this message]
2024-02-05 19:22 ` Bartosz Golaszewski
2024-02-06 12:30 ` Andy Shevchenko
2024-02-05 9:34 ` [PATCH v2 18/23] gpio: remove unnecessary checks from gpiod_to_chip() Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 19/23] gpio: add the can_sleep flag to struct gpio_device Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 20/23] gpio: add SRCU infrastructure " Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 21/23] gpio: protect the pointer to gpio_chip in gpio_device with SRCU Bartosz Golaszewski
2024-02-05 12:31 ` Andy Shevchenko
2024-02-05 13:30 ` Bartosz Golaszewski
2024-02-05 19:32 ` Bartosz Golaszewski
2024-02-05 19:36 ` Bartosz Golaszewski
2024-02-06 12:24 ` Andy Shevchenko
2024-02-06 12:57 ` Bartosz Golaszewski
2024-02-06 13:13 ` Andy Shevchenko
2024-02-06 13:23 ` Bartosz Golaszewski
2024-02-06 13:43 ` Andy Shevchenko
2024-02-05 9:34 ` [PATCH v2 22/23] gpio: remove the RW semaphore from the GPIO device Bartosz Golaszewski
2024-02-05 9:34 ` [PATCH v2 23/23] gpio: mark unsafe gpio_chip manipulators as deprecated Bartosz Golaszewski
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