linux-kernel - Re: [PATCH v2 1/2] irqchip/stm32: Add irq retrigger support

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Message-ID: <608d9c84813323ee3839f6ac21aa8f4e@kernel.org>
Date:   Wed, 19 Feb 2020 11:43:11 +0000
From:   Marc Zyngier <maz@...nel.org>
To:     Alexandre Torgue <alexandre.torgue@...com>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Jason Cooper <jason@...edaemon.net>,
        Linus Walleij <linus.walleij@...aro.org>, marex@...x.de,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 1/2] irqchip/stm32: Add irq retrigger support

On 2020-02-19 11:33, Alexandre Torgue wrote:
> Fix Marc email address
> 
> On 2/18/20 2:12 PM, Alexandre Torgue wrote:
>> This commit introduces retrigger support for stm32_ext_h chip.
>> It consists to rise the GIC interrupt mapped to an EXTI line.
>> 
>> Signed-off-by: Alexandre Torgue <alexandre.torgue@...com>
>> 
>> diff --git a/drivers/irqchip/irq-stm32-exti.c 
>> b/drivers/irqchip/irq-stm32-exti.c
>> index e00f2fa27f00..c971d115edb4 100644
>> --- a/drivers/irqchip/irq-stm32-exti.c
>> +++ b/drivers/irqchip/irq-stm32-exti.c
>> @@ -604,12 +604,24 @@ static void stm32_exti_h_syscore_deinit(void)
>>   	unregister_syscore_ops(&stm32_exti_h_syscore_ops);
>>   }
>>   +static int stm32_exti_h_retrigger(struct irq_data *d)
>> +{
>> +	struct stm32_exti_chip_data *chip_data = 
>> irq_data_get_irq_chip_data(d);
>> +	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
>> +	void __iomem *base = chip_data->host_data->base;
>> +	u32 mask = BIT(d->hwirq % IRQS_PER_BANK);
>> +
>> +	writel_relaxed(mask, base + stm32_bank->swier_ofst);
>> +
>> +	return irq_chip_retrigger_hierarchy(d);

Calling irq_chip_retrigger_hierarchy here is really odd. If the write
above has the effect of making the interrupt pending again, why do you
need to force the retrigger any further?

             M.
-- 
Jazz is not dead. It just smells funny...