linux-kernel - Re: [PATCH 1/2] linux/interrupt.h: allow "guard" notation to disable and reenable IRQ with valid IRQ check

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Message-ID: <d9096670-cd01-41c4-9186-847641c4368a@gmail.com>
Date: Thu, 22 Jan 2026 21:57:16 +0300
From: Sergey Shtylyov <sergei.shtylyov@...il.com>
To: Geert Uytterhoeven <geert@...ux-m68k.org>,
 Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc: Marek Vasut <marek.vasut+renesas@...lbox.org>,
 linux-input@...r.kernel.org, "Peter Zijlstra (Intel)"
 <peterz@...radead.org>, Cheng-Yang Chou <yphbchou0911@...il.com>,
 Dmitry Torokhov <dmitry.torokhov@...il.com>, Frank Li <Frank.Li@....com>,
 Geert Uytterhoeven <geert+renesas@...der.be>,
 Jinjie Ruan <ruanjinjie@...wei.com>,
 Krzysztof Kozlowski <krzysztof.kozlowski@....qualcomm.com>,
 Marc Zyngier <maz@...nel.org>, Thomas Gleixner <tglx@...nel.org>,
 linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH 1/2] linux/interrupt.h: allow "guard" notation to disable
 and reenable IRQ with valid IRQ check

On 1/22/26 7:31 PM, Geert Uytterhoeven wrote:
[...]

>>> @@ -242,6 +242,21 @@ extern void irq_wake_thread(unsigned int irq, void *dev_id);
>>>  DEFINE_LOCK_GUARD_1(disable_irq, int,
>>>                   disable_irq(*_T->lock), enable_irq(*_T->lock))
>>>
>>> +static inline void disable_valid_irq(unsigned int irq)
>>> +{
>>> +     if (irq > 0)
>>> +             disable_irq(irq);
>>> +}
>>
>> | $ grep " 0:" /proc/interrupts
>> |    0:         43          0          IO-APIC  2-edge      timer
>>
>> in other words, interrupt 0 is valid.
> 
> AFAIK, the x86 legacy timer interrupt is the sole remaining valid user
> of interrupt number zero.
> Nowadays lots of code assumes valid interrupt numbers are non-zero
> positive numbers.

   Makes me remember this commit:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce753ad1549cbe9ccaea4c06a1f5fa47432c8289

> Gr{oetje,eeting}s,
> 
>                         Geert
MBR, Sergey