From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751022AbdCNIiz (ORCPT ); Tue, 14 Mar 2017 04:38:55 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:40479 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750871AbdCNIiy (ORCPT ); Tue, 14 Mar 2017 04:38:54 -0400 Date: Tue, 14 Mar 2017 09:38:51 +0100 (CET) From: Thomas Gleixner To: Tony Lindgren cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] genirq: Fix handle_nested_irq() for IRQF_SHARED In-Reply-To: <20170314005240.18911-1-tony@atomide.com> Message-ID: References: <20170314005240.18911-1-tony@atomide.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, 13 Mar 2017, Tony Lindgren wrote: > Shared interrupts can be registered with handle_nested_irq(), but > currently only one of the registered handlers gets called. > > The use of shared interrupts with handle_nested_irq() is probably rare, > but at least a case of a shared VBUS interrupt between USB PHY and > battery charger drivers for a PMIC makes sense. > > Typically for_each_action_of_desc() gets called via handle_irq_event() > at _handle_irq_event_percpu(), but handle_nested_irq() is different > because of it's dummy irq_nested_primary_handler(). > > Let's fix the issue by calling the handler for all the entries in > the action list. > > Fixes: 399b5da29b9f ("genirq: Support nested threaded irq handling") It's not a fix, it's an extension. The nested facility was not meant to handle shared interrupts in the first place. I really hope that hardware folks finally understand that irq sharing is crap and broken... > Signed-off-by: Tony Lindgren > --- > kernel/irq/chip.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c > --- a/kernel/irq/chip.c > +++ b/kernel/irq/chip.c > @@ -348,9 +348,11 @@ void handle_nested_irq(unsigned int irq) > irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS); > raw_spin_unlock_irq(&desc->lock); > > - action_ret = action->thread_fn(action->irq, action->dev_id); > - if (!noirqdebug) > - note_interrupt(desc, action_ret); > + for_each_action_of_desc(desc, action) { > + action_ret = action->thread_fn(action->irq, action->dev_id); > + if (!noirqdebug) > + note_interrupt(desc, action_ret); This is wrong. See how __handle_irq_event_percpu() does this. But no need to resend. See: http://lkml.kernel.org/r/1488904098-5350-1-git-send-email-ckeepax@opensource.wolfsonmicro.com Thanks, tglx