linux-kernel - Re: [PATCH v3 05/13] genirq: Let purely flow-masked ONESHOT irqs through unmask_threaded

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Message-ID: <875ywa944c.mognet@arm.com>
Date:   Thu, 12 Aug 2021 14:36:35 +0100
From:   Valentin Schneider <valentin.schneider@....com>
To:     Marc Zyngier <maz@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Vincenzo Frascino <vincenzo.frascino@....com>
Subject: Re: [PATCH v3 05/13] genirq: Let purely flow-masked ONESHOT irqs through unmask_threaded_irq()

On 12/08/21 08:26, Marc Zyngier wrote:
> On Tue, 29 Jun 2021 13:50:02 +0100,
> Valentin Schneider <valentin.schneider@....com> wrote:
>> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
>> index ef30b4762947..e6d6d32ddcbc 100644
>> --- a/kernel/irq/manage.c
>> +++ b/kernel/irq/manage.c
>> @@ -1107,7 +1107,7 @@ static void irq_finalize_oneshot(struct irq_desc *desc,
>>  	desc->threads_oneshot &= ~action->thread_mask;
>>  
>>  	if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
>> -	    irqd_irq_masked(&desc->irq_data))
>> +	    (irqd_irq_masked(&desc->irq_data) | irqd_irq_flow_masked(&desc->irq_data)))
>>  		unmask_threaded_irq(desc);
>
> The bitwise OR looks pretty odd. It is probably fine given that both
> side of the expression are bool, but still. I can fix this locally.
>

Thomas suggested that back in v1:

  https://lore.kernel.org/lkml/87v98v4lan.ffs@nanos.tec.linutronix.de/

I did look at the (arm64) disassembly diff back then and was convinced by
what I saw, though I'd have to go do that again as I can't remember much
else.

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