linux-kernel - Re: [PATCH] thermal/drivers/qcom/lmh: Remove spurious IRQF

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Message-ID: <aX4amIuUFUtv7M2J@sirena.co.uk>
Date: Sat, 31 Jan 2026 15:07:04 +0000
From: Mark Brown <broonie@...nel.org>
To: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: Amit Kucheria <amitk@...nel.org>,
	Thara Gopinath <thara.gopinath@...il.com>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Zhang Rui <rui.zhang@...el.com>, Lukasz Luba <lukasz.luba@....com>,
	linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Aishwarya TCV <Aiswarya.TCV@....com>
Subject: Re: [PATCH] thermal/drivers/qcom/lmh: Remove spurious IRQF_ONESHOT

On Sat, Jan 31, 2026 at 08:59:03AM +0200, Dmitry Baryshkov wrote:
> On Fri, Jan 30, 2026 at 04:54:45PM +0000, Mark Brown wrote:

> > This warning is there because IRQF_ONESHOT is only meaningful when there is
> > a threaded interrupt handler and this driver does not register one. Just
> > remove IRQF_ONESHOT, it wasn't doing anything.

> I think it might be not that easy. The IRQ is level-triggered, with the
> IRQ source (if I'm not mistaken) cointinuing to be high level while CPU
> is overheated. By removing this IRQF_ONESHOT we might get an IRQ storm.

See the commit log for aef30c8d569c ("genirq: Warn about using
IRQF_ONESHOT without a threaded handler"), and note that a oneshot
interrupt will be unmasked if the main handler directly handles it and
returns IRQ_HANDLED instead of waking the thread with IRQ_WAKE_THREAD.
The handler in this driver unconditionally returns IRQ_HANDLED.

The above sounds like the interrupt needs to be edge triggered?

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