Messages in this thread |  | | From | Marc Zyngier <> | Subject | Re: [PATCH] genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs | Date | Sat, 15 Apr 2017 14:30:58 +0100 |
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On Sat, Apr 15 2017 at 11:08:31 am BST, Hans de Goede <hdegoede@redhat.com> wrote: > When requesting a shared irq with IRQF_TRIGGER_NONE then the irqaction > flags get filled with the trigger type from the irq_data: > > if (!(new->flags & IRQF_TRIGGER_MASK)) > new->flags |= irqd_get_trigger_type(&desc->irq_data); > > On the first setup_irq() the trigger type in irq_data is NONE when the > above code executes, then the irq is started up for the first time and > then the actual trigger type gets established, but that's too late to fix > up new->flags. > > When then a second user of the irq requests the irq with IRQF_TRIGGER_NONE > its irqaction's triggertype gets set to the actual trigger type and the > following check fails: > > if (!((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) > > Resulting in the request_irq failing with -EBUSY even though both > users requested the irq with IRQF_SHARED | IRQF_TRIGGER_NONE > > This commit fixes this by comparing the new irqaction's trigger type > to the trigger type stored in the irq_data which correctly reflects > the actual trigger type being used for the irq. > > Suggested-by: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > kernel/irq/manage.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index a4afe5c..d63e91f 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -1212,8 +1212,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > * set the trigger type must match. Also all must > * agree on ONESHOT. > */ > + unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data); > + > if (!((old->flags & new->flags) & IRQF_SHARED) || > - ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || > + (oldtype != (new->flags & IRQF_TRIGGER_MASK)) || > ((old->flags ^ new->flags) & IRQF_ONESHOT)) > goto mismatch;
Looks sensible to me.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
M. -- Jazz is not dead, it just smell funny.
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