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From: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
To: Linus Walleij <linusw@kernel.org>,
	Bartosz Golaszewski <brgl@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Kent Gibson <warthog618@gmail.com>,
	Adrian Ambrozewicz <aambrozewicz@nvidia.com>
Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>,
	stable@vger.kernel.org
Subject: [PATCH 0/5] gpiolib: improve concurrent access to the flags field of struct gpio_desc
Date: Wed, 04 Nov 2026 16:36:55 +0100	[thread overview]
Message-ID: <20261104-gpio-desc-flags-atomic-v1-0-e23cedf619ba@oss.qualcomm.com> (raw)

This is a follow-up to our discussion[1] about desc->flags and possible
races with users who don't/can't synchronize with other means.

It's an attempt to use try_cmpxchg() to update only the required flags
atomically where needed + minor fixes using atomic variants of bitops
where it makes sense.

[1] https://lore.kernel.org/all/20261015153714.GA105746@rigel/

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Bartosz Golaszewski (5):
      gpiolib: don't overwrite the entire flags field in gpiod_get_direction()
      gpio: shared: use atomic set_bit() for descriptor flags
      gpiolib: provide gpiod_update_flags()
      gpiolib: don't overwrite the entire flags field in gpiod_free_commit()
      gpio: cdev: don't overwrite the whole flags field when configuring lines

 drivers/gpio/gpiolib-cdev.c   | 118 +++++++++++++++++++++++-------------------
 drivers/gpio/gpiolib-shared.c |   6 +--
 drivers/gpio/gpiolib.c        |  29 +++++------
 drivers/gpio/gpiolib.h        |  21 ++++++++
 4 files changed, 103 insertions(+), 71 deletions(-)
---
base-commit: f1fa734d14164cddc063dbf2138c2feb38baab42
change-id: 20261104-gpio-desc-flags-atomic-cc963a1ccfd0

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>


             reply	other threads:[~2026-11-04 15:37 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-04 15:36 Bartosz Golaszewski [this message]
2026-11-04 15:36 ` [PATCH 1/5] gpiolib: don't overwrite the entire flags field in gpiod_get_direction() Bartosz Golaszewski
2026-11-04 15:36 ` [PATCH 2/5] gpio: shared: use atomic set_bit() for descriptor flags Bartosz Golaszewski
2026-11-04 15:36 ` [PATCH 3/5] gpiolib: provide gpiod_update_flags() Bartosz Golaszewski
2026-11-04 15:36 ` [PATCH 4/5] gpiolib: don't overwrite the entire flags field in gpiod_free_commit() Bartosz Golaszewski
2026-11-04 15:37 ` [PATCH 5/5] gpio: cdev: don't overwrite the whole flags field when configuring lines Bartosz Golaszewski
2026-11-04 21:55   ` Andy Shevchenko

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