From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Walleij Subject: Re: [RFC PATCH V2 1/8] irqdomain: Ensure type settings match for an existing mapping Date: Tue, 22 Dec 2015 11:00:37 +0100 Message-ID: References: <1450349309-8107-1-git-send-email-jonathanh@nvidia.com> <1450349309-8107-2-git-send-email-jonathanh@nvidia.com> <5673DB87.6040106@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , Jiang Liu , Stephen Warren , Thierry Reding , Kevin Hilman , Geert Uytterhoeven , Grygorii Strashko , Lars-Peter Clausen , Soren Brinkmann , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Tue, Dec 22, 2015 at 10:58 AM, Linus Walleij wrote: > On Fri, Dec 18, 2015 at 11:10 AM, Jon Hunter wrote: >> On 17/12/15 13:16, Linus Walleij wrote: >>> On Thu, Dec 17, 2015 at 11:48 AM, Jon Hunter wrote: >>>> + } else { >>>> + virq = irq_domain_alloc_descs(-1, 1, hwirq, >>>> + of_node_to_nid(of_node)); >>> >>> What is this all of a sudden? Not even mentioned in the >>> commit. Plus I bet ACPI need something else than OF nid >>> passed here. >> >> Do you mean the else part of all of the above? > > Yes > >> So in the current code, the else part calls irq_create_mapping() (...) > > No, not that... The fact that you all of a sudden have started > calling irq_domain_alloc_descs() which the function didn't do > before, totally changing the calling semantics for everyone in > the kernel, leading to the problem I then describe with this > potentially being called before the irqdomain for the irqchip > is initialized and descs getting "random" numbers. I see I didn't go into those details in my first answer. Hm, I guess I got uncertain and deleted it because I remember writing it... I am simply worries that starting to call irq_domain_alloc_descs() has unintended side effects, especially on platforms using legacy or simple irqdomains. Yours, Linus Walleij From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932534AbbLVKAl (ORCPT ); Tue, 22 Dec 2015 05:00:41 -0500 Received: from mail-oi0-f49.google.com ([209.85.218.49]:33880 "EHLO mail-oi0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932164AbbLVKAi (ORCPT ); Tue, 22 Dec 2015 05:00:38 -0500 MIME-Version: 1.0 In-Reply-To: References: <1450349309-8107-1-git-send-email-jonathanh@nvidia.com> <1450349309-8107-2-git-send-email-jonathanh@nvidia.com> <5673DB87.6040106@nvidia.com> Date: Tue, 22 Dec 2015 11:00:37 +0100 Message-ID: Subject: Re: [RFC PATCH V2 1/8] irqdomain: Ensure type settings match for an existing mapping From: Linus Walleij To: Jon Hunter Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , Jiang Liu , Stephen Warren , Thierry Reding , Kevin Hilman , Geert Uytterhoeven , Grygorii Strashko , Lars-Peter Clausen , Soren Brinkmann , "linux-kernel@vger.kernel.org" , "linux-tegra@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 On Tue, Dec 22, 2015 at 10:58 AM, Linus Walleij wrote: > On Fri, Dec 18, 2015 at 11:10 AM, Jon Hunter wrote: >> On 17/12/15 13:16, Linus Walleij wrote: >>> On Thu, Dec 17, 2015 at 11:48 AM, Jon Hunter wrote: >>>> + } else { >>>> + virq = irq_domain_alloc_descs(-1, 1, hwirq, >>>> + of_node_to_nid(of_node)); >>> >>> What is this all of a sudden? Not even mentioned in the >>> commit. Plus I bet ACPI need something else than OF nid >>> passed here. >> >> Do you mean the else part of all of the above? > > Yes > >> So in the current code, the else part calls irq_create_mapping() (...) > > No, not that... The fact that you all of a sudden have started > calling irq_domain_alloc_descs() which the function didn't do > before, totally changing the calling semantics for everyone in > the kernel, leading to the problem I then describe with this > potentially being called before the irqdomain for the irqchip > is initialized and descs getting "random" numbers. I see I didn't go into those details in my first answer. Hm, I guess I got uncertain and deleted it because I remember writing it... I am simply worries that starting to call irq_domain_alloc_descs() has unintended side effects, especially on platforms using legacy or simple irqdomains. Yours, Linus Walleij