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From: Linus Walleij <linus.walleij@linaro.org>
Date: Tue, 13 Feb 2024 22:29:45 +0100
Message-ID: <CACRpkdY5fVNJBhVDrCb0cbrsWAKAZBkCACUgSjWGoHqtnaJJtQ@mail.gmail.com>
Subject: Re: [PATCH 1/3] gpio: take the SRCU read lock in gpiod_hog()
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: 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>, 
	linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>, kernel test robot <oliver.sang@intel.com>
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On Tue, Feb 13, 2024 at 10:31=E2=80=AFAM Bartosz Golaszewski <brgl@bgdev.pl=
> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> gpiod_hog() may be called without the gpio_device SRCU read lock taken
> so we need to do it here as well. It's alright if someone else is
> already holding the lock as SRCU read critical sections can be nested.
>
> Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_devi=
ce with SRCU")
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.co=
m
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Looking at the CLASS() stuff I see this is definitely the way to go
with the code now that we face massive scaling. Nice work.

Yours,
Linus Walleij