Re: [PATCH v1 1/3] gpiolib: Introduce devm_gpiochip_dispose_irq_mappings()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] gpiolib: build failure in gpiochip_dispose_irq_mappings() without IRQ_DOMAIN
--

commit c8fefed15e55a94335f2d9f38c7ab3dbbe263c9b
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: Introduce devm_gpiochip_dispose_irq_mappings()

This commit introduces the devm_gpiochip_dispose_irq_mappings() helper in
drivers/gpio/gpiolib-devres.c to deduplicate disposing of GPIO chip IRQ
mappings on device removal.

> diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
> index 2ec825ffab7da..e7e6690d699e7 100644
> --- a/drivers/gpio/gpiolib-devres.c
> +++ b/drivers/gpio/gpiolib-devres.c
[ ... ]
> @@ -323,6 +324,38 @@ void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
>  }
>  EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
>  
> +struct gpiochip_irqdomain {
> +	struct gpio_chip *gc;
> +	struct irq_domain *domain;
> +};
> +
> +static void gpiochip_dispose_irq_mappings(struct device *dev, void *res)
> +{
> +	struct gpiochip_irqdomain *gcirq = res;
> +
> +	for (unsigned int i = 0; i < gcirq->gc->ngpio; i++)
> +		irq_dispose_mapping(irq_find_mapping(gcirq->domain, i));
> +}

[Severity: Low]
Will gpiochip_dispose_irq_mappings() in drivers/gpio/gpiolib-devres.c fail
to build when CONFIG_GPIOLIB=y and CONFIG_IRQ_DOMAIN is disabled?

In drivers/gpio/Makefile, gpiolib-devres.o is built whenever CONFIG_GPIOLIB
is enabled:

    obj-$(CONFIG_GPIOLIB)		+= gpiolib-devres.o

In drivers/gpio/Kconfig, GPIOLIB does not select IRQ_DOMAIN (only
GPIOLIB_IRQCHIP selects it).

In include/linux/irqdomain.h, irq_find_mapping() is only defined inside the
CONFIG_IRQ_DOMAIN block, while the fallback block for !CONFIG_IRQ_DOMAIN
provides a stub for irq_dispose_mapping() but omits irq_find_mapping():

    #else /* CONFIG_IRQ_DOMAIN */
    static inline void irq_dispose_mapping(unsigned int virq) { }
    static inline struct irq_domain *irq_find_matching_fwnode(...)
    {
            return NULL;
    }
    #endif /* !CONFIG_IRQ_DOMAIN */

Without a stub for irq_find_mapping() or a CONFIG_IRQ_DOMAIN guard, does
compiling drivers/gpio/gpiolib-devres.c with CONFIG_GPIOLIB=y and
CONFIG_IRQ_DOMAIN=n result in an implicit declaration error for
irq_find_mapping()?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261021204654.1001101-1-andriy.shevchenko@linux.intel.com?part=1