From: Thomas Gleixner <tglx@kernel.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Marek Vasut <marek.vasut+renesas@mailbox.org>
Cc: linux-input@vger.kernel.org,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Cheng-Yang Chou <yphbchou0911@gmail.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Frank Li <Frank.Li@nxp.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Jinjie Ruan <ruanjinjie@huawei.com>,
Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>,
Marc Zyngier <maz@kernel.org>,
linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH 1/2] linux/interrupt.h: allow "guard" notation to disable and reenable IRQ with valid IRQ check
Date: Fri, 23 Jan 2026 11:52:58 +0100 [thread overview]
Message-ID: <87h5sca9dh.ffs@tglx> (raw)
In-Reply-To: <20260122162206.9wrHkrTZ@linutronix.de>
On Thu, Jan 22 2026 at 17:22, Sebastian Andrzej Siewior wrote:
> On 2026-01-22 00:23:47 [+0100], Marek Vasut 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.
No. It's not really.
Interrupt number zero is a historic leftover and a mistake which is only
relevant to some oddball archaic architectures like x86 and others which
tried to mimic that.
The general agreement is that interrupt 0 is a legacy oddity and only
supported in very special cases. Everything else treats 0 as invalid.
Thanks,
tglx
next prev parent reply other threads:[~2026-01-23 10:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 23:23 [PATCH 1/2] linux/interrupt.h: allow "guard" notation to disable and reenable IRQ with valid IRQ check Marek Vasut
2026-01-21 23:23 ` [PATCH 2/2] Input: ili210x - convert to disable_valid_irq scoped guard Marek Vasut
2026-01-22 15:38 ` [PATCH 1/2] linux/interrupt.h: allow "guard" notation to disable and reenable IRQ with valid IRQ check Frank Li
2026-01-22 19:11 ` Marek Vasut
2026-01-22 16:22 ` Sebastian Andrzej Siewior
2026-01-22 16:31 ` Geert Uytterhoeven
2026-01-22 18:38 ` Dmitry Torokhov
2026-01-22 18:57 ` Sergey Shtylyov
2026-01-23 10:52 ` Thomas Gleixner [this message]
2026-01-25 5:30 ` Dmitry Torokhov
2026-01-27 9:14 ` Thomas Gleixner
2026-01-28 12:23 ` Marek Vasut
2026-01-28 13:49 ` Thomas Gleixner
2026-01-28 14:33 ` Marek Vasut
2026-02-12 18:44 ` Dmitry Torokhov
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