From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751804AbeFEKQb (ORCPT ); Tue, 5 Jun 2018 06:16:31 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:54252 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751619AbeFEKQ0 (ORCPT ); Tue, 5 Jun 2018 06:16:26 -0400 Subject: Re: [PATCH] irqchip/gic-v3-its: fix ITS queue timeout To: Yang Yingliang , marc.zyngier@arm.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <1528180225-16144-1-git-send-email-yangyingliang@huawei.com> From: Julien Thierry Message-ID: <834fde1b-5ae0-afc6-283f-2a470757e54a@arm.com> Date: Tue, 5 Jun 2018 11:16:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <1528180225-16144-1-git-send-email-yangyingliang@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yang, On 05/06/18 07:30, Yang Yingliang wrote: > When the kernel booted with maxcpus=x, 'x' is smaller > than actual cpu numbers, the TAs of offline cpus won't > be set to its->collection. > > If LPI is bind to offline cpu, sync cmd will use zero TA, > it leads to ITS queue timeout. Fix this by choosing a > online cpu, if there is no online cpu in cpu_mask. > > Signed-off-by: Yang Yingliang > --- > drivers/irqchip/irq-gic-v3-its.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 5416f2b..edd92a9 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -2309,7 +2309,9 @@ static int its_irq_domain_activate(struct irq_domain *domain, > cpu_mask = cpumask_of_node(its_dev->its->numa_node); > > /* Bind the LPI to the first possible CPU */ > - cpu = cpumask_first(cpu_mask); > + cpu = cpumask_first_and(cpu_mask, cpu_online_mask); > + if (!cpu_online(cpu)) Testing for cpu being online here feels a bit redundant. Since cpu is online if the cpumask_first_and returns a valid cpu, I think you could replace this test with: if (cpu >= nr_cpu_ids) > + cpu = cpumask_first(cpu_online_mask); > its_dev->event_map.col_map[event] = cpu; > irq_data_update_effective_affinity(d, cpumask_of(cpu)); > > @@ -2466,7 +2468,10 @@ static int its_vpe_set_affinity(struct irq_data *d, > bool force) > { > struct its_vpe *vpe = irq_data_get_irq_chip_data(d); > - int cpu = cpumask_first(mask_val); > + int cpu = cpumask_first_and(mask_val, cpu_online_mask); > + > + if (!cpu_online(cpu)) Same thing here. > + cpu = cpumask_first(cpu_online_mask); > > /* > * Changing affinity is mega expensive, so let's be as lazy as > Cheers, -- Julien Thierry