From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B5407340290; Fri, 23 Jan 2026 10:53:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769165583; cv=none; b=c+9Lu26OdOul27rdMyqqyhmV2cCJ86w09H7HD3QbYFTsfW0MYGNefhTxM6qTIw27rxde7e4VhnAeBWB8TWxOFOo44+DwF1UJkw7UmYv8hQkRJMV08l7agqphnOzxyebNonQmCOBe5o/E7/uXHPI1a3jw+WgpAjZX4ct0VqUNVqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769165583; c=relaxed/simple; bh=uLv8LO/KUhOdMpUkUDKLbVQl1Uwqg6NqoOUU7GrtXFQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=UcGZ2vu/ZlRWwLeG7I3FxoLRTg8rPTH8hPkI4rCZarvQ0ybXVmKqJKQ8+bdsQ75q/X2yfHnlsv/Z5KBuwCwcyXriKbBwNg34PU/IwHKEZS+nHpQShqa9khScUJdXjMp5P1DaqYnuVgfs7pYRLKppFmTOuGHI6HhbU5vSs80FzGw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cfTdr0HW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cfTdr0HW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE631C4CEF1; Fri, 23 Jan 2026 10:53:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769165582; bh=uLv8LO/KUhOdMpUkUDKLbVQl1Uwqg6NqoOUU7GrtXFQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=cfTdr0HWdlkTiJbSZZJmhH6y/hsnvK7ezJdzF+gHYnAp+2EHp+n+L+EukndFYXHg0 fJBYG3A15CRh97UVpfXoHByiZxoFrFNNW/ynrjCi3DrV4FDvkjOjg8Wbx7jBgB2rrD k5o4LxEKu2Rp+W8Giy8gct20T4y5Q3W8nBBKqOpWv6RLVRx8l9/mt0DpE/yAK9XZdO eBSHgXk8JW7mDeJ/cJqvY8xoRtgZEPshtedcUf0HPEWOhH5weDT/84DSlRGLdh46Tk ZiMDl+2PcL0m7gVE9ctZS85Vkk0CYvwMa+S9LwVxN7a+LjyoqerdNOtHTag5gU7K7Z 1TdqP0lRLmJgg== From: Thomas Gleixner To: Sebastian Andrzej Siewior , Marek Vasut Cc: linux-input@vger.kernel.org, "Peter Zijlstra (Intel)" , Cheng-Yang Chou , Dmitry Torokhov , Frank Li , Geert Uytterhoeven , Jinjie Ruan , Krzysztof Kozlowski , Marc Zyngier , 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 In-Reply-To: <20260122162206.9wrHkrTZ@linutronix.de> References: <20260121232522.154771-1-marek.vasut+renesas@mailbox.org> <20260122162206.9wrHkrTZ@linutronix.de> Date: Fri, 23 Jan 2026 11:52:58 +0100 Message-ID: <87h5sca9dh.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain 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