Re: [PATCH v2 7/8] arm64: dts: qcom: qcs404: Define APPS IOMMU

From: Bjorn Andersson
Date: Mon May 13 2019 - 14:30:14 EST


On Sun 12 May 21:54 PDT 2019, Vinod Koul wrote:

> On 09-05-19, 21:34, Bjorn Andersson wrote:
> > The APPS IOMMU provides contexts for FastRPC, MDP and WLAN, among other
> > things. Define these. We use the qcom_iommu binding because the
> ^^^
> Double spaces crept in..
>

That's to give you some breathing room while reading it - but not as
much as a new paragraph :)

> > firmware restrictions in incompatible with the arm-smmu.
> >
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/qcom/qcs404.dtsi | 85 ++++++++++++++++++++++++++++
> > 1 file changed, 85 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/qcs404.dtsi b/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > index b213f6acad76..fcde4f0334c2 100644
> > --- a/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > @@ -378,6 +378,91 @@
> > reg = <0x01937000 0x25000>;
> > };
> >
> > + apps_iommu: iommu@1e20000 {
> > + compatible = "qcom,qcs404-iommu", "qcom,msm-iommu-v1";
>
> Did we define qcom,qcs404-iommu in bindings, It does not seem to be
> there in this patch, next or integration one
>

No, this was entirely intended to fall back on the generic compatible.

That said, further testing of this series indicates that we have a
cache issue related to the SMMU. In working out this I came up with a
series of patches to the arm-smmu driver that allow us to use this with
the standard Qualcomm bootloader.

So let's ignore patch 7 and 8 in this series until we know how to deal
with the SMMU.

Regards,
Bjorn