Re: [PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants

Path	csiph.com!news.redatomik.org!weretis.net!feeder4.news.weretis.net!news.unit0.net!news.panservice.it!diesel.cu.mi.it!bofh.it!news.nic.it!robomod
From	Linus Walleij <linus.walleij@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants
Date	Wed, 15 Mar 2017 11:10:01 +0100
Message-ID	<tle2t-689-5@gated-at.bofh.it> (permalink)
References	<tj9gC-7KS-21@gated-at.bofh.it> <tj9zY-7Tv-5@gated-at.bofh.it>
Dkim-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=oulrladJV+u8CcNa4WPNPsigqrBhdGP+itUpXJbfTqQ=; b=bjOw1tKtpCji2wTvUor6dRKIYXul6NmPL4zCoD5zY1jSbYaeZfBH7jVEsoPoEzSDbI h5ub1BDHMcDCJc5fw19vw145hCz5juBtXgevsZcK+LsChtC4UBdNk0rphvvzXmBdrngb GlemYwmzP03HXlX5Z6yEkpUcrSaWeRM0tkqoE=
X-Google-Dkim-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=oulrladJV+u8CcNa4WPNPsigqrBhdGP+itUpXJbfTqQ=; b=ejfgeYU/6UKdVgVB0XFNVxMbnItPh0MVF5/RGbmgmRRs+4yDJjcsA5JhQEgE+Lsm5D 6ZhL+r1+7WE04P0YbGU0INIrLAZBZ0pI/R9k6gDLbJ+ZNhKfiZzGsM8zE5ReqB/Zmnue 1z/q3HBtbVtiukaYKoZAsNBYeXDepOAlV/GAmGul2g2gEo19Cdpy1NKEyHlFtGX6h3B9 eUZL9fk0UVA/q8TGx8p1HjAl2Ypi+Wh6i88MHwnmIcrE3h29OlRPh6y1Q4PlmliQGwhf YdsGs+ITRhmYj94YorLMkCg/iWtbwkAM8XAICWA498Ixptw66QB/PpU+Cqnn0OmwUV7k iezw==
X-Gm-Message-State	AFeK/H2kDHs8rts/WsdCw0IuPi4GXB/0396TlgmKVV13d1ZbuBdHTToGYt/MAqiQ4b7W8KRRGipMVuF5Oj3BsKXG
X-Received	by 10.107.20.193 with SMTP id 184mr3975453iou.61.1489572161254; Wed, 15 Mar 2017 03:02:41 -0700 (PDT)
MIME-Version	1.0
Content-Type	text/plain; charset=UTF-8
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	17
Organization	linux.* mail to news gateway
X-Original-Cc	William Breathitt Gray <vilhelm.gray@gmail.com>, Alexandre Courbot <gnurou@gmail.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Thomas Gleixner <tglx@linutronix.de>, "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>
X-Original-Date	Wed, 15 Mar 2017 11:02:40 +0100
X-Original-Message-ID	<CACRpkda_GtOT5_Xs6iNCbVqzDWQM6qWM2T7ctxoBa-4VmGK6hQ@mail.gmail.com>
X-Original-References	<cover.1489015238.git.julia@ni.com> <90f09a1e378d9858c4d79bd02e31512b96ef8de3.1489015238.git.julia@ni.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1601212

Show key headers only | View raw

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The ws16c48 gpio driver currently implements an irq_chip for handling
> interrupts; due to how irq_chip handling is done, it's necessary for the
> irq_chip methods to be invoked from hardirq context, even on a a
> real-time kernel.  Because the spinlock_t type becomes a "sleeping"
> spinlock w/ RT kernels, it is not suitable to be used with irq_chips.
>
> A quick audit of the operations under the lock reveal that they do only
> minimal, bounded work, and are therefore safe to do under a raw spinlock.
>
> Signed-off-by: Julia Cartwright <julia@ni.com>

Patch applied with William's ACK.

Yours,
Linus Walleij

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

Re: [PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants Linus Walleij <linus.walleij@linaro.org> - 2017-03-15 11:10 +0100

csiph-web