Re: [PATCH] pinctrl: ingenic: Convert to immutable irq chip

[Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>]

Marc Zyngier <maz@xxxxxxxxxx> writes:

> On 2022-06-09 11:00, Paul Cercueil wrote:
>> Hi Aidan,
>> Le mar., juin 7 2022 at 17:47:19 +0100, Aidan MacDonald
>> <aidanmacdonald.0x0@xxxxxxxxx> a écrit :
>>> Paul Cercueil <paul@xxxxxxxxxxxxxxx> writes:
>>> 
>>>>  Hi Aidan,
>>>>  Le mar., juin 7 2022 at 12:05:25 +0100, Aidan MacDonald
>>>>  <aidanmacdonald.0x0@xxxxxxxxx> a écrit :
>>>>>  Update the driver to use an immutable IRQ chip to fix this warning:
>>>>>      "not an immutable chip, please consider fixing it!"
>>>>>  Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
>>>>>  ---
>>>>>   drivers/pinctrl/pinctrl-ingenic.c | 33 ++++++++++++++++++-------------
>>>>>   1 file changed, 19 insertions(+), 14 deletions(-)
>>>>>  diff --git a/drivers/pinctrl/pinctrl-ingenic.c
>>>>>  b/drivers/pinctrl/pinctrl-ingenic.c
>>>>>  index 1ca11616db74..37258fb05be3 100644
>>>>>  --- a/drivers/pinctrl/pinctrl-ingenic.c
>>>>>  +++ b/drivers/pinctrl/pinctrl-ingenic.c
>>>>>  @@ -135,7 +135,6 @@ struct ingenic_pinctrl {
>>>>>   struct ingenic_gpio_chip {
>>>>>   	struct ingenic_pinctrl *jzpc;
>>>>>   	struct gpio_chip gc;
>>>>>  -	struct irq_chip irq_chip;
>>>>>   	unsigned int irq, reg_base;
>>>>>   };
>>>>>  @@ -3419,6 +3418,8 @@ static void ingenic_gpio_irq_enable(struct irq_data
>>>>>  *irqd)
>>>>>   	struct ingenic_gpio_chip *jzgc = gpiochip_get_data(gc);
>>>>>   	int irq = irqd->hwirq;
>>>>>  +	gpiochip_enable_irq(gc, irq);
>>>>>  +
>>>>>   	if (is_soc_or_above(jzgc->jzpc, ID_JZ4770))
>>>>>   		ingenic_gpio_set_bit(jzgc, JZ4770_GPIO_INT, irq, true);
>>>>>   	else if (is_soc_or_above(jzgc->jzpc, ID_JZ4740))
>>>>>  @@ -3443,6 +3444,8 @@ static void ingenic_gpio_irq_disable(struct
>>>>> irq_data
>>>>>  *irqd)
>>>>>   		ingenic_gpio_set_bit(jzgc, JZ4740_GPIO_SELECT, irq, false);
>>>>>   	else
>>>>>   		ingenic_gpio_set_bit(jzgc, JZ4730_GPIO_GPIER, irq, false);
>>>>>  +
>>>>>  +	gpiochip_disable_irq(gc, irq);
>>>>>   }
>>>>>   static void ingenic_gpio_irq_ack(struct irq_data *irqd)
>>>>>  @@ -3684,6 +3687,20 @@ static void ingenic_gpio_irq_release(struct
>>>>> irq_data
>>>>>  *data)
>>>>>   	return gpiochip_relres_irq(gpio_chip, data->hwirq);
>>>>>   }
>>>>>  +static const struct irq_chip ingenic_gpio_irqchip = {
>>>>>  +	.name			= "gpio",
>>>>>  +	.irq_enable		= ingenic_gpio_irq_enable,
>>>>>  +	.irq_disable		= ingenic_gpio_irq_disable,
>>>>>  +	.irq_unmask		= ingenic_gpio_irq_unmask,
>>>>>  +	.irq_mask		= ingenic_gpio_irq_mask,
>>>>>  +	.irq_ack		= ingenic_gpio_irq_ack,
>>>>>  +	.irq_set_type		= ingenic_gpio_irq_set_type,
>>>>>  +	.irq_set_wake		= ingenic_gpio_irq_set_wake,
>>>>>  +	.irq_request_resources	= ingenic_gpio_irq_request,
>>>>>  +	.irq_release_resources	= ingenic_gpio_irq_release,
>>>>>  +	.flags			= IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
>>>>>  +};
>>>>>  +
>>>>>   static int ingenic_pinmux_set_pin_fn(struct ingenic_pinctrl *jzpc,
>>>>>   		int pin, int func)
>>>>>   {
>>>>>  @@ -4172,20 +4189,8 @@ static int __init ingenic_gpio_probe(struct
>>>>>  ingenic_pinctrl *jzpc,
>>>>>   	if (!jzgc->irq)
>>>>>   		return -EINVAL;
>>>>>  -	jzgc->irq_chip.name = jzgc->gc.label;
>>>>>  -	jzgc->irq_chip.irq_enable = ingenic_gpio_irq_enable;
>>>>>  -	jzgc->irq_chip.irq_disable = ingenic_gpio_irq_disable;
>>>>>  -	jzgc->irq_chip.irq_unmask = ingenic_gpio_irq_unmask;
>>>>>  -	jzgc->irq_chip.irq_mask = ingenic_gpio_irq_mask;
>>>>>  -	jzgc->irq_chip.irq_ack = ingenic_gpio_irq_ack;
>>>>>  -	jzgc->irq_chip.irq_set_type = ingenic_gpio_irq_set_type;
>>>>>  -	jzgc->irq_chip.irq_set_wake = ingenic_gpio_irq_set_wake;
>>>>>  -	jzgc->irq_chip.irq_request_resources = ingenic_gpio_irq_request;
>>>>>  -	jzgc->irq_chip.irq_release_resources = ingenic_gpio_irq_release;
>>>>>  -	jzgc->irq_chip.flags = IRQCHIP_MASK_ON_SUSPEND;
>>>>>  -
>>>>>   	girq = &jzgc->gc.irq;
>>>>>  -	girq->chip = &jzgc->irq_chip;
>>>>>  +	gpio_irq_chip_set_chip(girq, &ingenic_gpio_irqchip);
>>>>  This will change each irq_chip's name to "gpio", do we want that?
>>>>  You didn't remove jzgc->irq_chip, so maybe what you could do is
>>>>  jzgc->irq_chip = ingenic_gpio_irqchip;
>>>>  jzgc->irq_chip.name = jzgc->gc.label;
>>>>  gpio_irq_chip_set_chip(girq, &jzgc->irq_chip);
>>>>  Thoughts?
>>>>  Cheers,
>>>>  -Paul
>>>> 
>>> I wondered that myself, but it doesn't seem to affect anything except
>>> what is displayed in /proc/interrupts. Is the name used anywhere else
>>> where it might cause confusion?
>> I don't really know. If it only really affects the display in
>> /proc/interrupts then I'm fine with it. In doubt, I'd prefer to keep
>> the existing names.
>> 
>>> The only similar case I could find was pinctrl-microchip-sgpio.c where
>>> microchip_sgpio_register_bank() is called in a loop and registers the
>>> same irq chip repeatedly, so it's probably(?) okay to do this here. It
>>> seems to defeat the point of immutable irqchips if they just have to be
>>> copied anyway...
>> The point of immutable irqchips is that they aren't modified by the
>> core, if I understand it correctly. Immutable doesn't mean it has to
>> be static const.
>
> I want these to be made const. I agree that the fancy string should
> be kept (sadly), as it is a userspace visible change, and we don't
> do that.
>
> You can solve it using the irq_print_chip() callback as part of
> your irq_chip structures. See 3344265a2692 for an example.
>
> Thanks,
>
>         M.

Thanks for the tip! I'll do that and send a v2.