Re: [PATCH v3 2/5] pinctrl: renesas: rzt2h: setup IRQ in .irq_{request,release}_resources()

[Geert Uytterhoeven]

On Sun, 13 Sept 2026 at 21:58, Cosmin Tanislav
<cosmin-gabriel.tanislav.xa@xxxxxxxxxxx> wrote:
> When exporting a GPIO using the deprecated sysfs GPIO API,
> gpio_is_visible() calls gpiod_to_irq() to determine whether a GPIO is
> IRQ-capable, which ends up using
> struct gpio_irq_chip::child_to_parent_hwirq().
>
> When using the GPIO character device, it is possible to request a line
> and to dynamically switch between using it as an IRQ or as a GPIO, by
> updating the edge detector.
>
> The current struct gpio_irq_chip::child_to_parent_hwirq() implementation
> makes the assumption that it will only be called with the intention of
> setting up the IRQ permanently, and that it will only be released when
> the IRQ domain is freed.
>
> Since we now know that this is not the case, take the following steps in
> order to properly handle that case.
>
> Implement struct irq_chip::irq_{request,release}_resources() based on
> the default GPIOCHIP_IRQ_RESOURCE_HELPERS implementations.
>
> Move the IRQ setup and release logic inside them.
>
> Keep the mapping logic inside ::child_to_parent_hwirq() to be able to
> provide a proper HW IRQ number, but do not actually setup the IRQ.
>
> Remove rzt2h_gpio_irq_domain_free() as its only purpose was to free the
> acquired IRQs. irq_domain_free_irqs_common() will still be set up as
> struct gpio_irq_chip::child_irq_domain_ops::free by
> gpiochip_hierarchy_setup_domain_ops().
>
> Cc: stable@xxxxxxxxxx
> Fixes: 829dde3369a9 ("pinctrl: renesas: rzt2h: Add GPIO IRQ chip to handle interrupts")
> Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@xxxxxxxxxxx>
> ---
>
> V3:
>  * no changes
>
> V2:
>  * reuse irq_idx in rzt2h_gpio_irq_request_resources()
>  * mention that irq_domain_free_irqs_common() is still wired up

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
i.e. will queue in renesas-pinctrl for v7.4.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds