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Date:   Wed, 24 Mar 2021 05:11:13 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Stephen Boyd <swboyd@chromium.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        Douglas Anderson <dianders@chromium.org>
Subject: Re: [PATCH] arm64: dts: qcom: trogdor: Add no-hpd to DSI bridge node
Message-ID: <YFqt0U+sUPiNGIkQ@pendragon.ideasonboard.com>
References: <20210324025534.1837405-1-swboyd@chromium.org>
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In-Reply-To: <20210324025534.1837405-1-swboyd@chromium.org>
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Hi Stephen,

Thank you for the patch.

On Tue, Mar 23, 2021 at 07:55:34PM -0700, Stephen Boyd wrote:
> We should indicate that we're not using the HPD pin on this device, per
> the binding document. Otherwise if code in the future wants to enable
> HPD in the bridge when this property is absent we'll be wasting power
> powering hpd when we don't use it on trogdor boards. We didn't notice
> this before because the kernel driver blindly disables hpd, but that
> won't be true for much longer.
> 
> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Cc: Douglas Anderson <dianders@chromium.org>
> Fixes: 7ec3e67307f8 ("arm64: dts: qcom: sc7180-trogdor: add initial trogdor and lazor dt")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> index 07c8b2c926c0..298af6d7fb4a 100644
> --- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> @@ -595,6 +595,8 @@ sn65dsi86_bridge: bridge@2d {
>  		clocks = <&rpmhcc RPMH_LN_BB_CLK3>;
>  		clock-names = "refclk";
>  
> +		no-hpd;
> +
>  		ports {
>  			#address-cells = <1>;
>  			#size-cells = <0>;

-- 
Regards,

Laurent Pinchart