[PATCH v8 11/12] iommu/arm-smmu-v3: Invoke pm_runtime before hw access

[Daniel Mentz]

On Tue, Jun 9, 2026 at 3:34 AM Pranjal Shrivastava <praan at google.com> wrote:
> > I'm not sure if I have a good suggestion here. Have you considered the
> > following: Do not call arm_smmu_handle_gerror() from
> > arm_smmu_runtime_suspend(). Instead, call disable_irq() at the end of
> > the suspend handler (and enable_irq() at the beginning of the resume
> > handler)?
>
> I thought about using disable_irq(), but I think doing it at the
> hardware level (IRQ_CTRL) is better.
>
> By disabling in IRQ_CTRL and keeping the manual arm_smmu_handle_gerror()
> call at the end of suspend, we ensure that we don't lose any gerror info
> We catch and handle any errors that occurred during the drain/quiesce
> phase right before the power-down.

I think the beauty of disable_irq() is that it synchronizes any
potentially running hard IRQ handler, which helps avoid races.