Re: [PATCH v9 4/6] iommu/arm-smmu-v3: Add CS_NONE quirk for CONFIG_TEGRA241_CMDQV

[Nicolin Chen]

On Mon, Jul 08, 2024 at 12:31:15PM +0100, Will Deacon wrote:
> > > As for arm_smmu_cmdq_needs_busy_polling, it doesn't really look
> > > very optimal to me. But if you insist on having an smmu option,
> > > we still have to take in the PATCH-3 in this series, enforcing
> > > an arm_smmu_cmdq_build_sync_cmd() call in the IRQ handler too.
> > > So, it would eventually look like [attachment].
> >
> > Please ignore the attachment. Since we are adding arm_smmu_impl,
> > I figure that we could add an arm_smmu_cmdq_impl too. There's an
> > another small feature that I didn't implement in this v9, while
> > being able to benefit from a cmdq impl now.
> >
> > The impl can also hold a boolean busy_polling, so we won't need
> > a global smmu option.
> 
> So /that/ might be overkill. Architectural queues can use polling, so I
> don't mind having that option in the driver and it should keep the number
> of impl hooks to a minimum.

OK. Let's make an option as you suggested.

> > I will send a new version asap, though I am not sure if we can
> > still make it to this cycle that we hoped for :-/
> 
> I'm in fixes-only mode at this point, especially since we've not had a
> linux-next for a while.

Sad that we missed again. Thanks for letting me know that..

Nicolin