On 20/03/2019 17:51, Robin Murphy wrote:
> On 12/03/2019 15:59, Marc Gonzalez wrote:
>
>> I still can't get the ethernet card to play ball. As soon as I set the link up,
>> the system hangs a few seconds, then reboots.
>>
>> Here are the relevant DT nodes:
>> (There's probably an error or 12 lurking in there)
>>
>> anoc1_smmu: arm,smmu@1680000 {
>> compatible = "qcom,msm8996-smmu-v2", "qcom,smmu-v2";
>> reg = <0x01680000 0x10000>;
>> #iommu-cells = <0>;
>
> That's almost certainly not what you want - note that the binding is
> only defined for 1 or 2 cells. The current Linux driver does actually
> happen to handle 0 cells, in which case it will assume every device uses
> Stream ID 0, but if the funky mappings in the SDM845 patch are anything
> to go by I doubt that's correct.
>
>> #global-interrupts = <0>;
>
> Ouch - not having a global fault interrupt will make this even more
> painful to debug. At least with that you can figure out what Stream IDs
> are in play by forcing stuff to fault.
Hello Robin,
Your insight is always appreciated!
I can't say I have wrapped my head around iommu-cells, iommu-map,
and iommu-map-mask (yet) or stream IDs.
FWIW, here is the DT node as it appears downstream:
https://source.codeaurora.org/quic/la/kernel/msm-4.4/tree/arch/arm/boot/dts/qcom/msm-arm-smmu-8998.dtsi?h=LE.UM.1.3.r3.25#n18
anoc1_smmu: arm,smmu-anoc1@1680000 {
status = "ok";
compatible = "qcom,smmu-v2";
reg = <0x1680000 0x10000>;
#iommu-cells = <0>;
qcom,register-save;
qcom,skip-init;
#global-interrupts = <0>;
interrupts = <GIC_SPI 364 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 365 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 366 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 367 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 368 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 369 IRQ_TYPE_EDGE_RISING>;
qcom,msm-bus,name = "smmu-bus-client-anoc1";
qcom,msm-bus,num-cases = <2>;
qcom,msm-bus,active-only;
qcom,msm-bus,num-paths = <1>;
/* aggre1_noc_clk */
qcom,msm-bus,vectors-KBps =
<84 10062 0 0>,
<84 10062 0 1000>;
};
There's even a rationale for #iommu-cells=0, albeit for a different board:
https://source.codeaurora.org/quic/la/kernel/msm-4.4/commit/arch/arm/boot/dts/qcom?h=LE.UM.1.3.r3.25&id=f1fa301f977f06dcf990c0452d85e2f67d8cbbf1
> There's currently a placeholder stream ID of "1" in the PCIe RC
> device tree node. The PCIe RC doesn't actually attach and doesn't
> need a stream ID though, the "1" was put there to get around an error
> caused by the fact that #iommu-cells was equal to 1 for the
> anoc1_smmu, even though it should have actually been 0. Fix all this
> by making #iommu-cells = <0> for the anoc1 SMMU and removing the
> bogus placeholder stream ID.
I can't say I understand this blurb.
Regards.
