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

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Melody Olvera <quic_molvera@quicinc.com>,
	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 10:36:02 +0300	[thread overview]
Message-ID: <CAA8EJprQoCQzr2x0JA9_b3MDE=oOTODyHD23debEL1MCE1mWBA@mail.gmail.com> (raw)
In-Reply-To: <9664a623-3c58-49e8-1b9a-69335d844448@linaro.org>

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.

-- 
With best wishes
Dmitry