Re: [PATCH v3 6/6] iommu: mtk_iommu: Lookup phandle to retrieve syscon to pericfg

[AngeloGioacchino Del Regno]

Il 16/06/22 08:30, Yong Wu ha scritto:
> On Mon, 2022-06-13 at 10:13 +0200, AngeloGioacchino Del Regno wrote:
> > Il 13/06/22 07:32, Yong Wu ha scritto:
> > > On Thu, 2022-06-09 at 12:08 +0200, AngeloGioacchino Del Regno
> > > wrote:
> > > > On some SoCs (of which only MT8195 is supported at the time of
> > > > writing),
> > > > the "R" and "W" (I/O) enable bits for the IOMMUs are in the
> > > > pericfg_ao
> > > > register space and not in the IOMMU space: as it happened already
> > > > with
> > > > infracfg, it is expected that this list will grow.
> > >
> > > Currently I don't see the list will grow. As commented before, In
> > > the
> > > lastest SoC, The IOMMU enable bits for IOMMU will be in ATF, rather
> > > than in this pericfg register region. In this case, Is this patch
> > > unnecessary? or we could add this patch when there are 2 SoCs use
> > > this
> > > setting at least?  what's your opinion?
> >
> > Perhaps I've misunderstood... besides, can you please check if
> > there's any
> > other SoC (not just chromebooks, also smartphone SoCs) that need this
> > logic?
>
> As far as I know, SmartPhone SoCs don't enable the infra iommu until
> now. they don't have this logic. I don't object this patch, I think we
> could add it when at least 2 SoCs need this.
>
> Thanks very much for help improving here.

Many thanks for checking that! Now that everything is clear, I can safely
go on with pushing a v4 of this series.

Thanks again!
Angelo