From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755931AbbIUJHY (ORCPT ); Mon, 21 Sep 2015 05:07:24 -0400 Received: from www.linutronix.de ([62.245.132.108]:35531 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753124AbbIUJHW (ORCPT ); Mon, 21 Sep 2015 05:07:22 -0400 Date: Mon, 21 Sep 2015 11:06:45 +0200 (CEST) From: Thomas Gleixner To: Marc Zyngier cc: Oleksij Rempel , linux-kernel@vger.kernel.org, jason@lakedaemon.net, Oleksij Rempel Subject: Re: [PATCH v2 2/2] ARM: irqchip: mxs: add Alpascale ASM9260 support In-Reply-To: <20150920122843.7cc93682@arm.com> Message-ID: References: <1442567922-14538-1-git-send-email-linux@rempel-privat.de> <1442567922-14538-3-git-send-email-linux@rempel-privat.de> <20150918114256.74ab823a@arm.com> <55FCF85E.8060909@rempel-privat.de> <20150920122843.7cc93682@arm.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 20 Sep 2015, Marc Zyngier wrote: > > Uff... in one of earliest reviews i was asked to add lock.. > > I also was asked to add asm9260 to some existing driver. Not sure if it > > is still making sense. > > Adding or removing a lock is not about what people ask you to do. It is > about requirements dictated by either the HW (you need to perform > a given sequence atomically with respect to another code sequence), the > kernel, or both. So I'd like to understand what is the underlying > reason for this lock. It is not disabling interrupts, so it could end > up being called in an interrupt context -> deadlock. The callback is always called with interrupts disabled, so that's a non issue. But still, the rationale for that lock is unclear. Thanks, tglx