Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754971AbdC1JNc (ORCPT ); Tue, 28 Mar 2017 05:13:32 -0400 Received: from mail-it0-f44.google.com ([209.85.214.44]:38265 "EHLO mail-it0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754800AbdC1JNb (ORCPT ); Tue, 28 Mar 2017 05:13:31 -0400 MIME-Version: 1.0 In-Reply-To: <9b15e28c4aeeade4b44e9a2bb06c12ded5d0990b.1490135047.git.julia@ni.com> References: <9b15e28c4aeeade4b44e9a2bb06c12ded5d0990b.1490135047.git.julia@ni.com> From: Linus Walleij Date: Tue, 28 Mar 2017 11:13:29 +0200 Message-ID: Subject: Re: [PATCH v2 8/9] gpio: 104-idio-16: make use of raw_spinlock variants To: Julia Cartwright Cc: William Breathitt Gray , Alexandre Courbot , "linux-kernel@vger.kernel.org" , linux-rt-users@vger.kernel.org, "linux-gpio@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 749 Lines: 19 On Tue, Mar 21, 2017 at 11:43 PM, Julia Cartwright wrote: > The 104-idio-16 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 > --- > New patch as of v2 of series. Patch applied to the GPIO tree with William's ACK. Yours, Linus Walleij