Re: [PATCH v2 2/6] genirq: fix irqchip_set_wake_parent if IRQCHIP_SKIP_SET_WAKE

[Grygorii Strashko]

On 08/13/2015 01:01 PM, Marc Zyngier wrote:
> On 12/08/15 18:45, Grygorii Strashko wrote:
> > The irqchip_set_wake_parent should not fail if IRQ chip
> > specifies IRQCHIP_SKIP_SET_WAKE. Otherwise, IRQ wakeup
> > configuration can't be propagated properly through IRQ
> > domains hierarchy.
> >
> > In case of TI OMAP DRA7 the issue reproduced with following
> > configuration:
> > ARM GIC<-OMAP wakeupgen<-TI CBAR<-GPIO<-GPIO pcf857x<-gpio_key
> >
> > gpio_key is wakeup source
> >
> > Failure is reproduced during suspend/resume to RAM:
> > suspend:
> >   - gpio_keys_suspend
> >     enable_irq_wake
> >       + pcf857x_irq_set_wake
> >         + omap_gpio_wake_enable
> >           + TI CBAR irq_chip_set_wake_parent
> >             + OMAP wakeupgen has no .irq_set_wake()
>
> Most importantly, wakeupgen has IRQCHIP_SKIP_SET_WAKE set.
>
> >             and -ENOSYS will be returned
> >
> > resume:
> >   - gpio_keys_resume
> >     + disable_irq_wake
> >       + irq_set_irq_wake
> >         + WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
> >
> > Fixes: 08b55e2a9208 ('genirq: Add irqchip_set_wake_parent')
> > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> > ---
> >   kernel/irq/chip.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> > index 6de638b..bdb1b9d 100644
> > --- a/kernel/irq/chip.c
> > +++ b/kernel/irq/chip.c
> > @@ -1024,6 +1024,10 @@ int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info)
> >   int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on)
> >   {
> >   	data = data->parent_data;
> > +
> > +	if (irq_data_get_irq_chip(data)->flags & IRQCHIP_SKIP_SET_WAKE)
> > +		return 0;
> > +
> >   	if (data->chip->irq_set_wake)
> >   		return data->chip->irq_set_wake(data, on);
>
> We have a more general issue with chip flags, and how they combine
> within a stack of irqchips.

Indeed. Problem looks similar to IRQCHIP_MASK_ON_SUSPEND flag usage.

> What if you remove the irq_chip_set_wake_parent from the crossbar
> driver, and instead set IRQCHIP_SKIP_SET_WAKE?

I've thought about this and it should work for me.
One question - what if crossbar will be not the last one in
IRQ domains hierarchy?


--
regards,
-grygorii
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