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From: Greg KH <gregkh@linuxfoundation.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org, pshete@nvidia.com,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Clark Williams <clrkwllms@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree
Date: Mon, 9 Mar 2026 14:38:28 +0100	[thread overview]
Message-ID: <2026030910-strength-relapse-8dee@gregkh> (raw)
In-Reply-To: <20260227071216.6dYMGnMj@linutronix.de>

On Fri, Feb 27, 2026 at 08:12:16AM +0100, Sebastian Andrzej Siewior wrote:
> On 2026-02-26 21:54:18 [-0500], Sasha Levin wrote:
> > Author: Prathamesh Shete <pshete@nvidia.com>
> > Date:   Thu Jan 8 05:01:03 2026 +0000
> > 
> >     soc/tegra: pmc: Fix unsafe generic_handle_irq() call
> >     
> >     [ Upstream commit e6d96073af681780820c94079b978474a8a44413 ]
> >     
> >     Currently, when resuming from system suspend on Tegra platforms,
> >     the following warning is observed:
> >     
> >     WARNING: CPU: 0 PID: 14459 at kernel/irq/irqdesc.c:666
> >     Call trace:
> >      handle_irq_desc+0x20/0x58 (P)
> >      tegra186_pmc_wake_syscore_resume+0xe4/0x15c
> >      syscore_resume+0x3c/0xb8
> >      suspend_devices_and_enter+0x510/0x540
> >      pm_suspend+0x16c/0x1d8
> >     
> >     The warning occurs because generic_handle_irq() is being called from
> >     a non-interrupt context which is considered as unsafe.
> >     
> >     Fix this warning by deferring generic_handle_irq() call to an IRQ work
> >     which gets executed in hard IRQ context where generic_handle_irq()
> >     can be called safely.
> >     
> >     When PREEMPT_RT kernels are used, regular IRQ work (initialized with
> >     init_irq_work) is deferred to run in per-CPU kthreads in preemptible
> >     context rather than hard IRQ context. Hence, use the IRQ_WORK_INIT_HARD
> >     variant so that with PREEMPT_RT kernels, the IRQ work is processed in
> >     hardirq context instead of being deferred to a thread which is required
> >     for calling generic_handle_irq().
> >     
> >     On non-PREEMPT_RT kernels, both init_irq_work() and IRQ_WORK_INIT_HARD()
> >     execute in IRQ context, so this change has no functional impact for
> >     standard kernel configurations.
> 
> sorry for not noticing this earlier: Instead of irq_work() and all this,
> I would suggest to revert this and simply switch to
> generic_handle_irq_safe() instead.

Can you send a patch upstream for this and tag it for stable?

thanks,

greg k-h

  reply	other threads:[~2026-03-09 13:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260227025419.2745361-1-sashal@kernel.org>
2026-02-27  7:12 ` Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree Sebastian Andrzej Siewior
2026-03-09 13:38   ` Greg KH [this message]
2026-03-09 13:40     ` Sebastian Andrzej Siewior

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