Re: [PATCH 1/5] dt-bindings: firmware: scm: Add QDU1000/QRU1000 compatibles

From: Melody Olvera <quic_molvera@quicinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Bhupesh Sharma <bhupesh.sharma@linaro.org>,
	<linux-arm-msm@vger.kernel.org>, <linux-mmc@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/5] dt-bindings: firmware: scm: Add QDU1000/QRU1000 compatibles
Date: Tue, 4 Oct 2022 11:08:30 -0500	[thread overview]
Message-ID: <bd50fcb0-f0a4-6552-e9df-c356c32972f1@quicinc.com> (raw)
In-Reply-To: <095742cb-61cc-af5d-848c-48b2ea5528ea@quicinc.com>


On 10/4/2022 10:52 AM, Melody Olvera wrote:
> On 10/4/2022 2:36 AM, Dmitry Baryshkov wrote:
>> On Tue, 4 Oct 2022 at 09:53, Krzysztof Kozlowski
>> <krzysztof.kozlowski@linaro.org> wrote:
>>> On 04/10/2022 00:14, Dmitry Baryshkov wrote:
>>>> On Tue, 4 Oct 2022 at 01:02, Melody Olvera <quic_molvera@quicinc.com> wrote:
>>>>> On 10/1/2022 4:25 AM, Krzysztof Kozlowski wrote:
>>>>>> On 01/10/2022 05:06, Melody Olvera wrote:
>>>>>>> Add compatibles for scm driver for QDU1000 and QRU1000 platforms.
>>>>>>>
>>>>>>> Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>
>>>>>>> ---
>>>>>>>  Documentation/devicetree/bindings/firmware/qcom,scm.yaml | 2 ++
>>>>>>>  1 file changed, 2 insertions(+)
>>>>>>>
>>>>>>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
>>>>>>> index c5b76c9f7ad0..b47a5dda3c3e 100644
>>>>>>> --- a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
>>>>>>> +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
>>>>>>> @@ -51,6 +51,8 @@ properties:
>>>>>>>            - qcom,scm-sm8250
>>>>>>>            - qcom,scm-sm8350
>>>>>>>            - qcom,scm-sm8450
>>>>>>> +          - qcom,scm-qdu1000
>>>>>>> +          - qcom,scm-qru1000
>>>> I think after seeing all the patchsets it's time to ask the following
>>>> question. Do we really need a duplicate compatibility families:
>>>> qdu1000 vs qru1000? I'd suggest using a single set of compatibile
>>>> strings in most of the cases.
>>>> Settle down onto a single name (qdu,qru, qdru, whatever) and define
>>>> distinct compat strings only when there is an actual difference?
>>>>
>>>> E.g .we don't have separate compatible strings for all the sda660,
>>>> apq8096, etc. unless this is required by the corresponding hardware
>>>> block not being compatible with corresponding sdm or msm counterpart.
>>>>
>>> I am not that fluent in Qualcomm naming, so let me ask - what are the
>>> differences between QDU and QRU?
>>>
>>> For compatible (and/or similar) devices the general recommendation is to
>>> have specific compatibles followed by fallback. Even if devices are
>>> very, very, very similar, usually the recommendation still stays.
>> Well, true. But in some cases we handle this by using a single set of
>> compatibles. Consider e.g. sa8155 vs sm8150 (sa8155 overrides just few
>> compats that differ). Or qrb5165 vs sm8250 (there is no separate
>> qrb5165.dtsi). APQ8096 (#include "msm8996.dtsi"). Etc.
>>
>> I'd say this really depends on the actual difference between qru and qdu.
> To add some clarification, there's pretty little functional
> difference between the QDU (Distributed Unit) and the QRU
> (Radio Unit); they're largely the same SoC from the kernel's
> standpoint. I wasn't sure if it made more sense to separate
> the compat strings or mash them together (using qdru to
> specify that it applies to both), so I kept separate compat
> strings in case there was a separate RU/DU use case down
> the line and also to avoid some confusion (I guess that
> didn't work though). It makes the most sense in my mind
> to just use the qdru compat string for the things that apply
> to both SoCs (which is most of what's submitted currently) and
> then we can do qdu/qru specific override strings for more
> specific drivers. 
> Thanks, Melody 
Fixed formatting.