From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753126AbcISJOo (ORCPT ); Mon, 19 Sep 2016 05:14:44 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:54383 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751581AbcISJOh (ORCPT ); Mon, 19 Sep 2016 05:14:37 -0400 Date: Mon, 19 Sep 2016 11:12:13 +0200 (CEST) From: Thomas Gleixner To: Marc Zyngier cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: Re: [PATCH] genirq: Skip chained interrupt trigger configuration if type is IRQ_TYPE_NONE In-Reply-To: <1474274967-15984-1-git-send-email-marc.zyngier@arm.com> Message-ID: References: <1474274967-15984-1-git-send-email-marc.zyngier@arm.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 19 Sep 2016, Marc Zyngier wrote: > There is no point in trying to configure the trigger of a chained > interrupt if no trigger information has been configured. At best > this is ignored, and at the worse this confuses the underlying > irqchip (which is likely not to handle such a thing), and > unnecessarily alarms the user. > > Only apply the configuration if type is not IRQ_TYPE_NONE. > > Reported-by: Geert Uytterhoeven > Fixes: 1e12c4a9393b ("genirq: Correctly configure the trigger on chained interrupts") > Link: https://lkml.kernel.org/r/CAMuHMdVW1eTn20=EtYcJ8hkVwohaSuH_yQXrY2MGBEvZ8fpFOg@mail.gmail.com > Signed-off-by: Marc Zyngier > --- > kernel/irq/chip.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c > index 6373890..26ba565 100644 > --- a/kernel/irq/chip.c > +++ b/kernel/irq/chip.c > @@ -820,6 +820,8 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, > desc->name = name; > > if (handle != handle_bad_irq && is_chained) { > + unsigned int type = irqd_get_trigger_type(&desc->irq_data); > + > /* > * We're about to start this interrupt immediately, > * hence the need to set the trigger configuration. > @@ -828,8 +830,10 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, > * chained interrupt. Reset it immediately because we > * do know better. > */ > - __irq_set_trigger(desc, irqd_get_trigger_type(&desc->irq_data)); > - desc->handle_irq = handle; > + if (type != IRQ_TYPE_NONE) { > + __irq_set_trigger(desc, type); > + desc->handle_irq = handle; Are you really sure that the handler should only be set when the trigger type is != NONE? I seriously doubt that this is correct. Thanks, tglx