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Message-ID: <78cd38f1-6ebc-097c-07f1-f7a028f07315@linaro.org>
Date:   Thu, 15 Dec 2022 19:01:44 +0100
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Subject: Re: [PATCH] arm64: dts: qcom: sc7280: enable IPA in
 sc7280-herobrine-lte-sku.dtsi
Content-Language: en-US
To:     Sibi Sankar <quic_sibis@quicinc.com>,
        Alex Elder <elder@linaro.org>, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, andersson@kernel.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>
 <a5ec259a-9f78-a54d-c15a-291f192ee220@quicinc.com>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <a5ec259a-9f78-a54d-c15a-291f192ee220@quicinc.com>
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On 15.12.2022 18:38, Sibi Sankar wrote:
> 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>
That + please flip the property order, as we're trying to
keep status last wherever possible.

Konrad
> 
>> 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>;
>>   };