Re: [PATCH v6 8/8] arm64: dts: qcom: sdm845: Add Q6V5 MSS node

[Sibi Sankar]

Hey Doug,

On 2019-02-28 02:33, Doug Anderson wrote:
> Hi,
>
> On Tue, Feb 26, 2019 at 3:54 PM Doug Anderson <dianders@xxxxxxxxxxxx> 
> wrote:
> > Hi,
> >
> > On Tue, Feb 5, 2019 at 9:13 PM Bjorn Andersson
> > <bjorn.andersson@xxxxxxxxxx> wrote:
> > >
> > > From: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
> > >
> > > This patch adds Q6V5 MSS remoteproc node for SDM845 SoCs.
> > >
> > > Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
> > > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > > ---
> > >
> > > Changes since v5:
> > > - None
> > >
> > >  arch/arm64/boot/dts/qcom/sdm845.dtsi | 58 ++++++++++++++++++++++++++++
> > >  1 file changed, 58 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > index 560c16616ee6..5c41f6fe3e1b 100644
> > > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > @@ -1612,6 +1612,64 @@
> > >                         };
> > >                 };
> > >
> > > +               mss_pil: remoteproc@4080000 {
> > > +                       compatible = "qcom,sdm845-mss-pil";
> > > +                       reg = <0 0x04080000 0 0x408>, <0 0x04180000 0 0x48>;
> > > +                       reg-names = "qdsp6", "rmb";
> >
> > I found that when I disabled IOMMU bypass by booting with
> > "arm-smmu.disable_bypass=y" that I'd get this failure:
> >
> > ---
> >
> > [   13.633776] qcom-q6v5-mss 4080000.remoteproc: MBA booted, loading 
> > mpss
> > [   13.647694] arm-smmu 15000000.iommu: Unexpected global fault, this
> > could be serious
> > [   13.660278] arm-smmu 15000000.iommu: GFSR 0x80000002, GFSYNR0
> > 0x00000000, GFSYNR1 0x00000781, GFSYNR2 0x00000000
> > ...
> > [   14.648830] qcom-q6v5-mss 4080000.remoteproc: MPSS header
> > authentication timed out
> > [   14.657141] qcom-q6v5-mss 4080000.remoteproc: port failed halt
> > [   14.664983] remoteproc remoteproc0: can't start rproc
> > 4080000.remoteproc: -110
> >
> > ---
> >
> > Adding "iommus = <&apps_smmu 0x781 0>;" here fixed my problem.  NOTE
> > that I'm no expert on IOMMUs so you should confirm that this is right,
> > but if it is then maybe you could include it in the next spin of the
> > series?  I got the "0x781" just by looking at the value of the GFSYNR1
> > in the above splat.  I wasn't sure what to put for the mask so I put
> > 0x0.
>
> Upon more testing the "iommus" line that I came up with avoids the
> global fault but doesn't actually work.  I just get:
>
> qcom-q6v5-mss 4080000.remoteproc: failed to allocate mdt buffer

AFAIK modem does not have a smmu in front of it.

We have reserved memory nodes for mba and mpss,
however for mdt authentication we just rely on
dma_alloc_attrs with DMA_ATTR_FORCE_CONTIGUOUS
for allocation which seems to fail here.

> I'm hoping someone from Qualcomm can help out here and say how this
> should be solved.  Thanks!

Yeah I'll enable arm-smmu.disable_bypass and
have a go at booting modem.

> -Doug

--
-- Sibi Sankar --
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.