Re: [PATCH v3 3/5] gpio: gpiolib: Allow free() callback to be overridden

Marc Zyngier
2022-05-12T11:23:04Z

On Wed, 11 May 2022 19:32:08 +0100,
Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
>
> Allow free() callback to be overridden from irq_domain_ops for
> hierarchical chips.
>
> This allows drivers to free any resources which are allocated during
> populate_parent_alloc_arg().

Do you mean more than the fwspec? I don't see this being used.

There is also the question of why we need to have dynamic allocation
for the fwspec itself. Why isn't that a simple stack allocation in the
context of gpiochip_hierarchy_irq_domain_alloc()?

M.

>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> drivers/gpio/gpiolib.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index b7694171655c..d36c4a965efc 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1187,15 +1187,18 @@ static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
> ops->activate = gpiochip_irq_domain_activate;
> ops->deactivate = gpiochip_irq_domain_deactivate;
> ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
> - ops->free = irq_domain_free_irqs_common;
>
> /*
> - * We only allow overriding the translate() function for
> + * We only allow overriding the translate() and free() functions for
> * hierarchical chips, and this should only be done if the user
> - * really need something other than 1:1 translation.
> + * really need something other than 1:1 translation for translate()
> + * callback and free if user wants to free up any resources which
> + * were allocated during callbacks, for example populate_parent_alloc_arg.
> */
> if (!ops->translate)
> ops->translate = gpiochip_hierarchy_irq_domain_translate;
> + if (!ops->free)
> + ops->free = irq_domain_free_irqs_common;
> }
>
> static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
> --
> 2.25.1
>
>

--
Without deviation from the norm, progress is not possible.