Re: [PATCH 1/2] irqchip: irq-mst: Add MStar interrupt controller support

[Marc Zyngier]

On 2020-08-19 14:31, Mark-PK Tsai wrote:
> From: Marc Zyngier <maz@xxxxxxxxxx>
>
> > > +
> > > +static int mst_intc_domain_alloc(struct irq_domain *domain, unsigned
> > > int virq,
> > > +				 unsigned int nr_irqs, void *data)
> > > +{
> > > +	int i;
> > > +	irq_hw_number_t hwirq;
> > > +	struct irq_fwspec parent_fwspec, *fwspec = data;
> > > +	struct mst_intc_chip_data *cd = (struct mst_intc_chip_data
> > > *)domain->host_data;
> >
> > No cast necessary here.
> >
> > > +
> > > +	/* Not GIC compliant */
> > > +	if (fwspec->param_count != 3)
> > > +		return -EINVAL;
> > > +
> > > +	/* No PPI should point to this domain */
> > > +	if (fwspec->param[0])
> > > +		return -EINVAL;
> > > +
> > > +	if (fwspec->param[1] >= cd->nr_irqs)
> >
> > This condition is bogus, as it doesn't take into account the nr_irqs
> > parameter.
>
>
> The hwirq number need to be in the irq map range. (property:
> mstar,irqs-map-range)
> If it's not, it must be incorrect configuration.

I agree. And since you are checking whether the configuration is 
correct,
it'd better be completely correct.

> So how about use the condition as following?
>
> if (hwirq >= cd->nr_irqs)
> 	return -EINVAL;

Again, this says nothing of the validity of (hwirq + nr_irqs - 1)...

> > > +		return -EINVAL;
> > > +
> > > +	hwirq = fwspec->param[1];
> > > +	for (i = 0; i < nr_irqs; i++)
> > > +		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> > > +					      &mst_intc_chip,
> > > +					      domain->host_data);

... which you are using here.

        M.
--
Jazz is not dead. It just smells funny...