Re: Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree

Re: Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree

[Sebastian Andrzej Siewior]

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.

Sebastian

Re: Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree

[Greg KH]

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

Re: Patch "soc/tegra: pmc: Fix unsafe generic_handle_irq() call" has been added to the 6.19-stable tree

[Sebastian Andrzej Siewior]

On 2026-03-09 14:38:28 [+0100], Greg KH wrote:
> > 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?

This was meant for the developer and maintainer of the patch, not for
the stable team.
I will follow up if they don't respond…

> thanks,
> 
> greg k-h

Sebastian