Re: [Freedreno] [PATCH v7 6/6] arm6: dts: qcom: sm845: Set the compatible string for the GPU SMMU

[Rob Clark]

On Thu, Jun 4, 2020 at 3:02 PM Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
>
> On Thu, Jun 04, 2020 at 02:27:21PM -0700, Rob Clark wrote:
> > On Thu, Jun 4, 2020 at 1:57 PM Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
> > >
> > > Set the qcom,adreno-smmu compatible string for the GPU SMMU to enable
> > > split pagetables.
> > >
> > > Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> > > ---
> > >
> > >  arch/arm64/boot/dts/qcom/sdm845.dtsi | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > index 8eb5a31346d2..8b15cd74e9ba 100644
> > > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > @@ -3556,7 +3556,7 @@
> > >                 };
> > >
> > >                 adreno_smmu: iommu@5040000 {
> > > -                       compatible = "qcom,sdm845-smmu-v2", "qcom,smmu-v2";
> > > +                       compatible = "qcom,adreno-smmu", "qcom,smmu-v2";
> >
> > Should this be something like:
> >
> >    compatible = "qcom,adreno-smmu", "qcom,sdm845-smmu-v2", "qcom,smmu-v2";
> >
> > so that new dtb still works with old kernel?
>
> As far as I know qcom,sdm845-smmu-v2 never was actually used unless we were
> doing the parsing trick somewhere.

I *think* it has a use queued up for v5.8 for the
select-direct-mapping stuff?  I'm not 100% sure of the status of that
off the top of my head.

BR,
-R

> Jordan
>
> > >                         reg = <0 0x5040000 0 0x10000>;
> > >                         #iommu-cells = <1>;
> > >                         #global-interrupts = <2>;
> > > --
> > > 2.17.1
> > >
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