Re: [PATCH] arm64: dts: sdm845: Add iommus property to qup1

Doug Anderson
2019-06-04T22:48:30Z

Hi,

On Tue, Jun 4, 2019 at 3:37 PM Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Tue 04 Jun 15:29 PDT 2019, Stephen Boyd wrote:
>
> > The SMMU that sits in front of the QUP needs to be programmed properly
> > so that the i2c geni driver can allocate DMA descriptors. Failure to do
> > this leads to faults when using devices such as an i2c touchscreen where
> > the transaction is larger than 32 bytes and we use a DMA buffer.
> >
>
> I'm pretty sure I've run into this problem, but before we marked the
> smmu bypass_disable and as such didn't get the fault, thanks.
>
> > arm-smmu 15000000.iommu: Unexpected global fault, this could be serious
> > arm-smmu 15000000.iommu: GFSR 0x00000002, GFSYNR0 0x00000002, GFSYNR1 0x000006c0, GFSYNR2 0x00000000
> >
> > Add the right SID and mask so this works.
> >
> > Cc: Sibi Sankar <sibis@codeaurora.org>
> > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> > arch/arm64/boot/dts/qcom/sdm845.dtsi | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > index fcb93300ca62..2e57e861e17c 100644
> > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > @@ -900,6 +900,7 @@
> > #address-cells = <2>;
> > #size-cells = <2>;
> > ranges;
> > + iommus = <&apps_smmu 0x6c0 0x3>;
>
> According to the docs this stream belongs to TZ, the HLOS stream should
> be 0x6c3.

Since you've already got the docs in front of you, how about looking
up the value for qup0 so we can fix both of 'em?

-Doug