Date:   Mon, 27 Feb 2023 19:02:41 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To:     Krishna chaitanya chundru <quic_krichai@quicinc.com>
Cc:     helgaas@kernel.org, linux-pci@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        mka@chromium.org, quic_vbadigan@quicinc.com,
        quic_hemantk@quicinc.com, quic_nitegupt@quicinc.com,
        quic_skananth@quicinc.com, quic_ramkri@quicinc.com,
        swboyd@chromium.org, dmitry.baryshkov@linaro.org,
        svarbanov@mm-sol.com, agross@kernel.org, andersson@kernel.org,
        konrad.dybcio@somainline.org, lpieralisi@kernel.org,
        robh@kernel.org, kw@linux.com, bhelgaas@google.com,
        linux-phy@lists.infradead.org, vkoul@kernel.org, kishon@ti.com,
        mturquette@baylibre.com, linux-clk@vger.kernel.org,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>
Subject: Re: [PATCH V1] arm64:dts:qcom:sc7280: mark memory of PCIe as cache
 coherent
Message-ID: <20230227133241.GA3647@thinkpad>
References: <1677490575-29092-1-git-send-email-quic_krichai@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1677490575-29092-1-git-send-email-quic_krichai@quicinc.com>
Precedence: bulk

Please fix the subject as:

arm64: dts: qcom: sc7280: Mark PCIe controller as cache coherent

On Mon, Feb 27, 2023 at 03:06:15PM +0530, Krishna chaitanya chundru wrote:
> Mark the PCIe node as dma-coherent as the devices on PCIe bus are
> cache coherent.
> 

But this is a bug fix actually. If the controller is not marked as cache
coherent, then kernel will try to ensure coherency during dma-ops and that may
cause data corruption.

So please add fixes tag and CC stable.

Thanks,
Mani

> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  arch/arm64/boot/dts/qcom/sc7280.dtsi | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> index bdcb749..8f4ab6b 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> @@ -2131,6 +2131,8 @@
>  			pinctrl-names = "default";
>  			pinctrl-0 = <&pcie1_clkreq_n>;
>  
> +			dma-coherent;
> +
>  			iommus = <&apps_smmu 0x1c80 0x1>;
>  
>  			iommu-map = <0x0 &apps_smmu 0x1c80 0x1>,
> -- 
> 2.7.4
> 

-- 
மணிவண்ணன் சதாசிவம்