From: Kent Gibson <warthog618@gmail.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
andy@kernel.org
Subject: Re: [PATCH 4/4] gpiolib: cdev: replace locking wrappers for gpio_device with guards
Date: Wed, 20 Dec 2023 20:53:14 +0800 [thread overview]
Message-ID: <ZYLjuqxXylKPYeYP@rigel> (raw)
In-Reply-To: <CAMRc=MeXa5g6iQNYF4W+vGL+kgRTyVjFB-yXE_UBpuTnn2ZKng@mail.gmail.com>
On Wed, Dec 20, 2023 at 01:30:57PM +0100, Bartosz Golaszewski wrote:
> On Wed, Dec 20, 2023 at 1:23 PM Kent Gibson <warthog618@gmail.com> wrote:
> >
> > >
> >
> > It would be read and write guards for the gpio_device.
> > cdev would only be using the read flavour.
> > And possibly named something other than read/write as the purpose is to
> > prevent (read) or allow (write) object removal.
> >
> > I though that would be clearer than having to reference gpiolib.h to see
> > what gdev->sem covers, and allow you to change the locking
> > mechanism later and not have to update cdev.
> >
>
> I still prefer open-coded guards here for clarity. I hope that with
> SRCU in gpiolib.c, we'll get rid of locking in cdev entirely anyway.
>
Ok, it is your object so I should use it the way you want it used.
Btw, before I go pushing out a v2, do you have an answer on whether
gpio_ioctl() requires a guard, as mentioned in the cover letter?
Is the fact there is an active ioctl on the chardev sufficient in
itself to keep the gpio_device alive?
Cheers,
Kent.
next prev parent reply other threads:[~2023-12-20 12:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-20 1:51 [PATCH 0/4] gpiolib: cdev: guard tidying Kent Gibson
2023-12-20 1:51 ` [PATCH 1/4] gpiolib: cdev: include overflow.h Kent Gibson
2023-12-20 1:51 ` [PATCH 2/4] gpiolib: cdev: allocate linereq using kvzalloc() Kent Gibson
2023-12-20 14:30 ` Andy Shevchenko
2023-12-20 14:53 ` Kent Gibson
2023-12-20 14:58 ` Andy Shevchenko
2023-12-20 1:51 ` [PATCH 3/4] gpiolib: cdev: replace locking wrappers for config_mutex with guards Kent Gibson
2023-12-20 1:51 ` [PATCH 4/4] gpiolib: cdev: replace locking wrappers for gpio_device " Kent Gibson
2023-12-20 11:55 ` Linus Walleij
2023-12-20 12:05 ` Bartosz Golaszewski
2023-12-20 12:13 ` Kent Gibson
2023-12-20 12:16 ` Bartosz Golaszewski
2023-12-20 12:23 ` Kent Gibson
2023-12-20 12:30 ` Bartosz Golaszewski
2023-12-20 12:53 ` Kent Gibson [this message]
2023-12-20 13:19 ` Bartosz Golaszewski
2023-12-20 13:28 ` Kent Gibson
2023-12-20 13:47 ` Bartosz Golaszewski
2023-12-20 13:53 ` Kent Gibson
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