Re: [PATCH v2 13/18] arm64: dts: qcom: sc7180: Add compat qcom,mdss-dsi-ctrl-sc7180

From: Doug Anderson <dianders@chromium.org>
To: "Bryan O'Donoghue" <bryan.odonoghue@linaro.org>
Cc: robdclark@gmail.com, quic_abhinavk@quicinc.com,
	dmitry.baryshkov@linaro.org, krzysztof.kozlowski+dt@linaro.org,
	robh+dt@kernel.org, quic_mkrishn@quicinc.com,
	linux-arm-msm@vger.kernel.org, Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@somainline.org>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Rajendra Nayak <rnayak@codeaurora.org>,
	Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Subject: Re: [PATCH v2 13/18] arm64: dts: qcom: sc7180: Add compat qcom,mdss-dsi-ctrl-sc7180
Date: Tue, 8 Nov 2022 08:41:21 -0800	[thread overview]
Message-ID: <CAD=FV=Up7yFEG_5JRBOOzpeQWBhXhoceWszO7G91zJKOUDSMpQ@mail.gmail.com> (raw)
In-Reply-To: <7a0c6afd-e757-46f6-5837-576070e966ec@linaro.org>

Hi,

On Tue, Nov 8, 2022 at 4:16 AM Bryan O'Donoghue
<bryan.odonoghue@linaro.org> wrote:
>
> On 08/11/2022 00:24, Doug Anderson wrote:
> > This seems fine, but I don't think it matches your bindings. Your
> > bindings says you can have one compatible string. It could be
> > "qcom,mdss-dsi-ctrl-sc7180" or it could be "qcom,mdss-dsi-ctrl".
> > ...but your device tree has two compatible strings: the SoC specific
> > one and the fallback one. You need to change your bindings to make
> > this work.
>
> With the update in this series the binding has a required const.
>
> If you drop back to just "qcom,mdss-dsi-ctrl-sc7180" you get a warning
> like this.
>
> arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dtb: dsi@ae94000:
> compatible: ['qcom,mdss-dsi-ctrl-sc7180'] is too short
>
> If you just have 'qcom,mdss-dsi-ctrl' you get
>
> arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dtb: dsi@ae94000:
> compatible:0: 'qcom,mdss-dsi-ctrl' is not one of
> ['qcom,dsi-ctrl-6g-qcm2290', 'qcom,mdss-dsi-ctrl-apq8064',
> 'qcom,mdss-dsi-ctrl-msm8916', 'qcom,mdss-dsi-ctrl-msm8974',
> 'qcom,mdss-dsi-ctrl-msm8996', 'qcom,mdss-dsi-ctrl-sc7180',
> 'qcom,mdss-dsi-ctrl-sc7280', 'qcom,mdss-dsi-ctrl-sdm630',
> 'qcom,mdss-dsi-ctrl-sdm660', 'qcom,mdss-dsi-ctrl-sdm845',
> 'qcom,mdss-dsi-ctrl-sm8250']

Huh. I must have missed something then. Ah, I see the problem. Since
you didn't CC me on the bindings change I searched myself. I found
patch #7 in your series ("dt-bindings: msm: dsi-controller-main: Add
compatible strings for every current SoC"). In that patch everything
is flat. I didn't notice patch #8 in your series which changes this. I
would just get the compatibles right the right time. Looking at patch
#8 I see that Dmitry already suggested this.

So that means this is fine with me. A slight nit that I suspect Bjorn
would prefer you to blow past the 80 column limit and put both
compatibles on one line, but it's not huge in my mind.

Reviewed-by: Douglas Anderson <dianders@chromium.org>