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Message-ID: <a5ec259a-9f78-a54d-c15a-291f192ee220@quicinc.com>
Date:   Thu, 15 Dec 2022 23:08:20 +0530
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Subject: Re: [PATCH] arm64: dts: qcom: sc7280: enable IPA in
 sc7280-herobrine-lte-sku.dtsi
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To:     Alex Elder <elder@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <agross@kernel.org>
CC:     <elder@kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20221208183837.505454-1-elder@linaro.org>
From:   Sibi Sankar <quic_sibis@quicinc.com>
In-Reply-To: <20221208183837.505454-1-elder@linaro.org>
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Alex,

Thanks for the patch.

On 12/9/22 00:08, Alex Elder wrote:
> IPA is only needed on a platform if it includes a modem, and not all
> SC7280 SoC variants do.  The file "sc7280-herobrine-lte-sku.dtsi" is
> used to encapsulate definitions related to Chrome OS SC7280 devices
> where a modem is present, and that's the proper place for the IPA
> node to be enabled.
> 
> Currently IPA is enabled in "sc7280-idp.dtsi", which is included by
> DTS files for Qualcomm reference platforms (all of which include the
> modem).  That also includes "sc7280-herobrine-lte-sku.dtsi", so
> enabling IPA there would make it unnecessary for "sc7280-idp.dtsi"
> to enable it.
> 
> The only other place IPA is enabled is "sc7280-qcard.dtsi".
> That file is included only by "sc7280-herobrine.dtsi", which
> is (eventually) included only by these top-level DTS files:
>    sc7280-herobrine-crd.dts
>    sc7280-herobrine-herobrine-r1.dts
>    sc7280-herobrine-evoker.dts
>    sc7280-herobrine-evoker-lte.dts
>    sc7280-herobrine-villager-r0.dts
>    sc7280-herobrine-villager-r1.dts
>    sc7280-herobrine-villager-r1-lte.dts
> All of but two of these include "sc7280-herobrine-lte-sku.dtsi", and
> for those cases, enabling IPA there means there is no need for it to
> be enabled in "sc7280-qcard.dtsi".
> 
> The two remaining cases will no longer enable IPA as a result of
> this change:
>    sc7280-herobrine-evoker.dts
>    sc7280-herobrine-villager-r1.dts
> Both of these have "lte" counterparts, and are meant to represent
> board variants that do *not* have a modem.
> 
> This is exactly the desired configuration.
> 
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---
>   arch/arm64/boot/dts/qcom/sc7280-herobrine-lte-sku.dtsi | 5 +++++
>   arch/arm64/boot/dts/qcom/sc7280-idp.dtsi               | 5 -----
>   arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi             | 5 -----
>   3 files changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine-lte-sku.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine-lte-sku.dtsi
> index ad66e5e9db4ed..956708397f035 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-herobrine-lte-sku.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine-lte-sku.dtsi
> @@ -34,3 +34,8 @@ &remoteproc_mpss {
>   &rmtfs_mem {
>   	reg = <0x0 0x9c900000 0x0 0x800000>;
>   };
> +
> +&ipa {
> +	status = "okay";
> +	modem-init;
> +};

nit; You'll probably want to move the ipa node above remoteproc node to
maintain sorting.

Reviewed-by: Sibi Sankar <quic_sibis@quicinc.com>
Tested-by: Sibi Sankar <quic_sibis@quicinc.com>

> diff --git a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> index f7efb9966afd1..0ddbe7f732bd9 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> @@ -376,11 +376,6 @@ &gpi_dma1 {
>   	status = "okay";
>   };
>   
> -&ipa {
> -	status = "okay";
> -	modem-init;
> -};
> -
>   &lpass_cpu {
>   	status = "okay";
>   
> diff --git a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
> index df49564ae6dc1..cd6ee84b36fd4 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
> @@ -336,11 +336,6 @@ vreg_bob: bob {
>   
>   /* ADDITIONS TO NODES DEFINED IN PARENT DEVICE TREE FILES */
>   
> -&ipa {
> -	status = "okay";
> -	modem-init;
> -};
> -
>   &lpass_va_macro {
>   	vdd-micb-supply = <&vreg_bob>;
>   };