linux-kernel - Re: [PATCH v5 2/9] drivers: irqchip: Add STM32 external interrupts support

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Date:   Tue, 20 Sep 2016 17:28:53 +0200
From:   Alexandre Torgue <alexandre.torgue@...com>
To:     Thomas Gleixner <tglx@...utronix.de>
CC:     Mark Rutland <mark.rutland@....com>, <devicetree@...r.kernel.org>,
        Daniel Thompson <daniel.thompson@...aro.org>,
        Jason Cooper <jason@...edaemon.net>, <arnd@...db.de>,
        Marc Zyngier <marc.zyngier@....com>, <bruherrera@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        <linux-kernel@...r.kernel.org>, <linux-gpio@...r.kernel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        <lee.jones@...aro.org>, <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v5 2/9] drivers: irqchip: Add STM32 external interrupts
 support

Thomas,

On 09/20/2016 04:02 PM, Thomas Gleixner wrote:
> On Tue, 20 Sep 2016, Alexandre Torgue wrote:
>> On 09/20/2016 02:44 PM, Thomas Gleixner wrote:
>>> Free will be called when a interrupt in the child domain is torn down,
>>> i.e. when irq_domain_free_irqs() is called. And it will be called for both
>>> domains like the alloc callback is invoked on both domains via
>>> irq_domain_alloc_irqs().
>>
>> Thanks Thomas for this clarification (I'm sure now that we need .free
>> callbacks).
>> irq_domain_free_irqs() is called in 2 scenario:
>> 1- when issue occurs in irq_create_fwspec_mapping()
>> 2- when irq_dispose_mapping() is called
>>
>> Case 2 is the one I tested some times ago. In this case, I need to mask
>> interrupts in .free callback of EXTI (parent) domain to avoid spurious
>> interrupts.
>
> And why would irq_dispose_mapping() be called on an unmasked, i.e. active,
> interrupt? The masking is just papering over that.

Ok. So my test was wrong and irq_dispose_mapping() has to be called when 
irq is masked (for example just  after free_irq()). For sure in this 
case the mask inside exti free callback has no sens (catch :))

I will change .free callback by:

static void stm32_exti_free(struct irq_domain *d, unsigned int virq,
			    unsigned int nr_irqs)
{
	struct irq_data *data = irq_domain_get_irq_data(d, virq);
	irq_domain_reset_irq_data(data);
}


so if you agree I will resend only patches concerning stm32 exti driver 
[1],[2],[3],[4]

Thanks for your time.

alex


>
> Thanks,
>
> 	tglx
>