2017-10-18 12:13 GMT+02:00 Marc Zyngier <[email protected]>:
>
[snip!]
> It looks to me that this is all because the irq_sim creation is a bit awkward.
> You end-up with all kind of exotic interfaces because you don't know the base
> of the irq range at creation time.
>
> How about something like this:
>
> diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
> index 24caabf1a0f7..484c3544c0d1 100644
> --- a/kernel/irq/irq_sim.c
> +++ b/kernel/irq/irq_sim.c
> @@ -49,7 +49,8 @@ static void irq_sim_handle_irq(struct irq_work *work)
> * @sim: The interrupt simulator object to initialize.
> * @num_irqs: Number of interrupts to allocate
> *
> - * Returns 0 on success and a negative error number on failure.
> + * Returns the interrupt base on success and a negative error number
> + * on failure.
> */
> int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
> {
> @@ -78,7 +79,7 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
> init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq);
> sim->irq_count = num_irqs;
>
> - return 0;
> + return sim->irq_base;
> }
> EXPORT_SYMBOL_GPL(irq_sim_init);
>
> You can then deal with the offset directly in your driver, as you're
> guaranteed a 1:1 mapping.
>
This is what we have now in next for iio. The thing is we want to get
rid of irq_base from the iio driver and store it (and relevant logic)
in irq_sim to have less code in the caller. Otherwise we duplicate
this info.
Thanks,
Bartosz
