Re: [PATCH] dt-bindings: qcom: geni-se: Fix '#address-cells' & '#size-cells' related dt-binding error

[Bhupesh Sharma]

On 1/16/23 9:24 PM, Konrad Dybcio wrote:
> On 16.01.2023 16:43, Bhupesh Sharma wrote:
> > On Mon, 16 Jan 2023 at 13:23, Krzysztof Kozlowski
> > <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> > > On 15/01/2023 22:33, Bhupesh Sharma wrote:
> > > > On Sun, 15 Jan 2023 at 20:57, Krzysztof Kozlowski
> > > > <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> > > > > On 13/01/2023 21:10, Bhupesh Sharma wrote:
> > > > > > Fix the following '#address-cells' & '#size-cells' related
> > > > > > dt-binding error:
> > > > > >
> > > > > >     $ make dtbs_check
> > > > > >
> > > > > >     From schema: Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml
> > > > > >          arch/arm64/boot/dts/qcom/sm4250-oneplus-billie2.dtb: geniqup@4ac0000:
> > > > > >                #address-cells:0:0: 2 was expected
> > > > > >        From schema: Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml
> > > > >
> > > > > Don't we want rather to unify the soc address range?
> > > >
> > > > Well, the assumption in the original dt-bindings was that every reg
> > > > variable is 4 * u32 wide (as most new qcom SoCs set #address- and
> > > > #size-cells to <2>). However, that is not the case for all of the
> > > > SoCs.
> > >
> > > Hm, which device of that SoC cannot be used with address/size cells 2?
> >
> > As noted in the git log already the geniqup on sm6115 / sm4250 cannot
> > be used with address/size cells 2 (See:
> > https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/qcom/sm6115.dtsi#L795)
> SM6115 (and pretty much every other arm64 msm platform newer than 8916)
> should be using addr/size-cells = 2 along with (dma-)ranges of 36 bit, as
> that's what their smmus use and otherwise some addresses may get cut off
> in translation, or so the story went with 845 N years ago.. We can either
> pursue this patch or I can submit the 2-cell-ification if you don't plan on
> adding more nodes shortly


Have you tested this combination on SM6115 like SoCs with various IPs? I 
have tried a few experiments in the past and not all IPs work well with 
36-bit DMA ranges (atleast not on the boards I have).

So, I think it might lead to more breakage (unless we are sure of a 
well-tested fix). A simpler patch to fix the dt-bindings looks more 
useful IMO.

Thanks,
Bhupesh