From: "Zhao, Yuanyuan" <yuanyuan.zhao@hxt-semitech.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: "tglx@linutronix.de" <tglx@linutronix.de>,
"jason@lakedaemon.net" <jason@lakedaemon.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"Zheng, Joey" <yu.zheng@hxt-semitech.com>,
"Wang, Dongsheng" <dongsheng.wang@hxt-semitech.com>
Subject: RE: [RESEND 1/1] gic: its: Make sure a LPI is discarded before free.
Date: Wed, 9 Jan 2019 09:29:41 +0000 [thread overview]
Message-ID: <c81f42aa93904353bbeac590da7b0945@HXTBJIDCEMVIW02.hxtcorp.net> (raw)
In-Reply-To: <20190109074324.6445118d@why.wild-wind.fr.eu.org>
Hi Marc:
Thank you for your reply.
As you said, APIs such as free_irq will deactivate irq
before free it. But deactivation is not forced by every API,
for example irq_dispose_mapping. So I think it's better to check
that irq was deactivated as expected.
BRs,
Yuanyuan
> -----Original Message-----
> From: Marc Zyngier [mailto:marc.zyngier@arm.com]
> Sent: 2019年1月9日 15:43
> To: Zhao, Yuanyuan <yuanyuan.zhao@hxt-semitech.com>
> Cc: tglx@linutronix.de; jason@lakedaemon.net; linux-
> kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; Zheng, Joey
> <yu.zheng@hxt-semitech.com>; Wang, Dongsheng <dongsheng.wang@hxt-
> semitech.com>
> Subject: Re: [RESEND 1/1] gic: its: Make sure a LPI is discarded before free.
>
> On Wed, 9 Jan 2019 11:53:27 +0800
> Zhao Yuanyuan <yuanyuan.zhao@hxt-semitech.com> wrote:
>
> Hi Zhao,
>
> > Its device will be removed after all events be freed.
> > Undisarded events can lead to unpredictable behaviar.
> >
> > Signed-off-by: Zhao Yuanyuan <yuanyuan.zhao@hxt-semitech.com>
> > ---
> > drivers/irqchip/irq-gic-v3-its.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/irqchip/irq-gic-v3-its.c
> > b/drivers/irqchip/irq-gic-v3-its.c
> > index db20e99..4fee008 100644
> > --- a/drivers/irqchip/irq-gic-v3-its.c
> > +++ b/drivers/irqchip/irq-gic-v3-its.c
> > @@ -2572,6 +2572,10 @@ static void its_irq_domain_free(struct
> irq_domain *domain, unsigned int virq,
> > virq + i);
> > u32 event = its_get_event_id(data);
> >
> > + /* Discard irq before free */
> > + if (irqd_is_activated(d))
> > + its_send_discard(its_dev, event);
> > +
> > /* Mark interrupt index as unused */
> > clear_bit(event, its_dev->event_map.lpi_map);
> >
>
> But we already do send a discard on deactivate, which logically happens
> before we free the domain. So what are you fixing here?
>
> Thanks,
>
> M.
> --
> Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2019-01-09 9:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-20 8:20 [PATCH 1/1] gic: its: Make sure a LPI is discarded before free Zhao Yuanyuan
2019-01-09 3:53 ` [RESEND " Zhao Yuanyuan
2019-01-09 7:43 ` Marc Zyngier
2019-01-09 9:29 ` Zhao, Yuanyuan [this message]
2019-01-09 9:52 ` Marc Zyngier
2019-01-10 9:42 ` Zhao, Yuanyuan
2019-01-10 12:55 ` Marc Zyngier
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