From: andy.shevchenko@gmail.com
To: William Breathitt Gray <william.gray@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@intel.com>,
brgl@bgdev.pl, linus.walleij@linaro.org,
linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org
Subject: Re: [PATCH 1/3] gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module
Date: Sat, 17 Sep 2022 11:59:22 +0300 [thread overview]
Message-ID: <YyWMai1UZPaBbsOx@surfacebook> (raw)
In-Reply-To: <YyNIxWS0sneUKas0@fedora>
Thu, Sep 15, 2022 at 11:46:13AM -0400, William Breathitt Gray kirjoitti:
> On Tue, Sep 13, 2022 at 07:16:23PM +0300, Andy Shevchenko wrote:
> > On Sun, Sep 11, 2022 at 04:34:38PM -0400, William Breathitt Gray wrote:
...
> > > + if (value)
> > > + set_bit(offset, state->out_state);
> > > + else
> > > + clear_bit(offset, state->out_state);
> >
> > assign_bit()
> >
> > But I'm wondering why do you need the atomic bitops under the lock?
>
> I don't think atomic bitops are necessary in this case because of the
> lock as you pointedly out, but I felt using these made the intention of
> the code clearer. Is there a non-atomic version of assign_bit(), or do
> you recommend I use bitwise operations directly here instead?
__assign_bit()
Hint: All __ prefixed bitops (for a single bit operation!) are considered
non-atomic. There are exceptions when no __-variant of op is present, but
it not the case here AFAICS.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2022-09-17 8:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-11 20:34 [PATCH 0/3] Introduce the ACCES IDIO-16 GPIO library module William Breathitt Gray
2022-09-11 20:34 ` [PATCH 1/3] gpio: idio-16: " William Breathitt Gray
2022-09-13 16:16 ` Andy Shevchenko
2022-09-15 15:46 ` William Breathitt Gray
2022-09-17 8:59 ` andy.shevchenko [this message]
2022-09-11 20:34 ` [PATCH 2/3] gpio: 104-idio-16: Utilize the idio-16 GPIO library William Breathitt Gray
2022-09-13 16:19 ` Andy Shevchenko
2022-09-13 16:25 ` William Breathitt Gray
2022-09-11 20:34 ` [PATCH 3/3] gpio: pci-idio-16: " William Breathitt Gray
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