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Message-ID: <886befb2-2be2-4db0-b205-b3d1043cde62@linaro.org>
Date: Tue, 16 Apr 2024 16:39:25 +0200
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Subject: Re: [PATCH v1] arm64: dts: qcom: sc7280: Remove CTS/RTS configuration
To: Luca Weiss <luca.weiss@fairphone.com>,
 Viken Dadhaniya <quic_vdadhani@quicinc.com>,
 cros-qcom-dts-watchers@chromium.org, andersson@kernel.org,
 swboyd@chromium.org, robh@kernel.org, krzk+dt@kernel.org,
 linux-arm-msm@vger.kernel.org, conor+dt@kernel.org,
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 rajpat@codeaurora.org, mka@chromium.org, rojay@codeaurora.org
Cc: quic_msavaliy@quicinc.com, quic_anupkulk@quicinc.com
References: <20240416105650.2626-1-quic_vdadhani@quicinc.com>
 <D0LINETM8WNA.27BORT75W1N0C@fairphone.com>
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From: Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <D0LINETM8WNA.27BORT75W1N0C@fairphone.com>
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On 4/16/24 13:38, Luca Weiss wrote:
> On Tue Apr 16, 2024 at 12:56 PM CEST, Viken Dadhaniya wrote:
>> Remove CTS and RTS pinctrl configuration for UART5 node as
>> it's designed for debug UART for all the board variants of the
>> sc7280 chipset.
>>
>> Also change compatible string to debug UART.
> 
> This change has little to do with the SoC design though and is dependent
> on the usage on a given board, right? Also the QCM6490 datasheet
> mentions gpio21 & gpio22 can be used for UART_CTS and UART_RFR.

Yeah, using it as a debug uart doesn't rule out flow control I don't think

> 
> But at least consistency-wise this change makes sense, in practically
> all other SoCs one UART is marked as geni-debug-uart.
> 
> But with this patch you should then also remove some overrides that are
> placed in various boards already?
> 
> arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts:     compatible = "qcom,geni-debug-uart";
> arch/arm64/boot/dts/qcom/qcm6490-idp.dts:       compatible = "qcom,geni-debug-uart";
> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts:   compatible = "qcom,geni-debug-uart";
> arch/arm64/boot/dts/qcom/sc7280-idp.dtsi:       compatible = "qcom,geni-debug-uart";
> arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi:     compatible = "qcom,geni-debug-uart";

Definitely

Konrad