Re: [Patch Part2 v4 01/31] irqdomain: Introduce new interfaces to support hierarchy irqdomains

[Thomas Gleixner]

On Tue, 4 Nov 2014, Jiang Liu wrote:
>  /* Number of irqs reserved for a legacy isa controller */
>  #define NUM_ISA_INTERRUPTS	16
> @@ -64,6 +66,16 @@ struct irq_domain_ops {
>  	int (*xlate)(struct irq_domain *d, struct device_node *node,
>  		     const u32 *intspec, unsigned int intsize,
>  		     unsigned long *out_hwirq, unsigned int *out_type);
> +
> +#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
> +	/* extended V2 interfaces to support hierarchy irq_domains */
> +	int (*alloc)(struct irq_domain *d, unsigned int virq,
> +		     unsigned int nr_irqs, void *arg);
> +	void (*free)(struct irq_domain *d, unsigned int virq,
> +		     unsigned int nr_irqs);
> +	int (*activate)(struct irq_domain *d, struct irq_data *irq_data);
> +	int (*deactivate)(struct irq_domain *d, struct irq_data *irq_data);

Why do we have a return value here? Especially the deactivate one
makes no sense at all.

> +extern int irq_domain_activate_irq(struct irq_data *irq_data);
> +extern int irq_domain_deactivate_irq(struct irq_data *irq_data);

And here.

> @@ -178,6 +179,7 @@ int irq_startup(struct irq_desc *desc, bool resend)
>  	irq_state_clr_disabled(desc);
>  	desc->depth = 0;
>  
> +	irq_domain_activate_irq(&desc->irq_data);

We do not check it and we cannot do here AFAICT.

>  	if (desc->irq_data.chip->irq_startup) {
>  		ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
>  		irq_state_clr_masked(desc);
> @@ -199,6 +201,7 @@ void irq_shutdown(struct irq_desc *desc)
>  		desc->irq_data.chip->irq_disable(&desc->irq_data);
>  	else
>  		desc->irq_data.chip->irq_mask(&desc->irq_data);
> +	irq_domain_deactivate_irq(&desc->irq_data);

Ditto.

So the return value for irq_domain_deactivate_irq() is silly to begin
with, but also the return value for irq_domain_activate_irq() does not
really make sense. We've allocated the resources for the interrupt
already down the hierarchy chain. So there is no reason why the actual
activation should fail.

Thanks,

	tglx
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