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Date:   Mon, 5 Dec 2022 13:07:16 +0100
From:   Johan Hovold <johan@kernel.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     Johan Hovold <johan+linaro@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Andy Gross <agross@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Bart Van Assche <bvanassche@acm.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-scsi@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: ufs: qcom: allow 'dma-coherent' property
Message-ID: <Y43e9KRDsTCS5VI4@hovoldconsulting.com>
References: <20221205100837.29212-1-johan+linaro@kernel.org>
 <20221205100837.29212-2-johan+linaro@kernel.org>
 <20221205115906.GA20192@thinkpad>
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On Mon, Dec 05, 2022 at 05:29:06PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Dec 05, 2022 at 11:08:36AM +0100, Johan Hovold wrote:
> > UFS controllers may be cache coherent and must be marked as such in the
> > devicetree to avoid data corruption.
> > 
> > This is specifically needed on recent Qualcomm platforms like SC8280XP.
> > 
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> >  Documentation/devicetree/bindings/ufs/qcom,ufs.yaml | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> > index f2d6298d926c..1f1d286749c0 100644
> > --- a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> > +++ b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> > @@ -44,6 +44,8 @@ properties:
> >      minItems: 8
> >      maxItems: 11
> >  
> > +  dma-coherent: true
> > +
> 
> This property is not applicable to all SoCs. So setting true here will make it
> valid for all.

Yes, it would be a valid, but it will only be added to the DTs of SoCs
that actually require it. No need to re-encode the dtsi in the binding.

Johan