Re: [PATCH v5 2/9] drivers: irqchip: Add STM32 external interrupts support

From: Thomas Gleixner
Date: Tue Sep 13 2016 - 11:24:03 EST

On Fri, 9 Sep 2016, Alexandre TORGUE wrote:
> +static void stm32_exti_free(struct irq_domain *d, unsigned int virq,
> + unsigned int nr_irqs)
> +{
> + struct irq_data *data = irq_get_irq_data(virq);
> +
> + irq_gc_mask_clr_bit(data->parent_data);

I have a hard time to understand this. The irq domain is not hierarchical.

> + irq_domain_reset_irq_data(data);

> + domain = irq_domain_add_linear(node, nr_exti,
> + &irq_exti_domain_ops, NULL);

It's a simple linear domain. So how can data->parent_data be a valid
irq_data pointer? Answer: It can't!

But it doesn't blow up in your face simply because the alloc/free callbacks
are never invoked for simple non hierarchical domains. So you should have
removed that stuff after copying some other irqchip driver.