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Message-ID: <6f08d466-9589-ebff-c38d-bf9015a0f6ad@linaro.org>
Date:   Mon, 16 Jan 2023 21:32:39 +0530
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Subject: Re: [PATCH] dt-bindings: qcom: geni-se: Fix '#address-cells' &
 '#size-cells' related dt-binding error
To:     Konrad Dybcio <konrad.dybcio@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        agross@kernel.org, andersson@kernel.org,
        linux-kernel@vger.kernel.org, bhupesh.linux@gmail.com,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org
References: <20230113201038.267449-1-bhupesh.sharma@linaro.org>
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 <23b4551c-db79-d859-c037-6ed3c8a11883@linaro.org>
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From:   Bhupesh Sharma <bhupesh.sharma@linaro.org>
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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@linaro.org> wrote:
>>>
>>> On 15/01/2023 22:33, Bhupesh Sharma wrote:
>>>> On Sun, 15 Jan 2023 at 20:57, Krzysztof Kozlowski
>>>> <krzysztof.kozlowski@linaro.org> 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