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.zyng...@arm.com] > Sent: 2019年1月9日 15:43 > To: Zhao, Yuanyuan <yuanyuan.z...@hxt-semitech.com> > Cc: t...@linutronix.de; ja...@lakedaemon.net; linux- > ker...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; Zheng, Joey > <yu.zh...@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.z...@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.z...@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.
