Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 7 Nov 2022 22:41:08 -0600
From:   Bjorn Andersson <andersson@kernel.org>
To:     Yassine Oudjana <yassine.oudjana@gmail.com>
Cc:     Andy Gross <agross@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Stephen Boyd <sboyd@kernel.org>, phone-devel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Yassine Oudjana <y.oudjana@protonmail.com>
Subject: Re: [PATCH] arm64: dts: qcom: msm8996pro-xiaomi-scorpio: Remove DSI
 PHY clocks from MMCC
Message-ID: <20221108044108.se3et4do5q2dspsb@builder.lan>
References: <20221107114016.356112-1-y.oudjana@protonmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20221107114016.356112-1-y.oudjana@protonmail.com>
Precedence: bulk

On Mon, Nov 07, 2022 at 02:40:17PM +0300, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
> 
> Having DSI PHY clocks listed in the MMCC node while MDSS is disabled makes
> it defer probe indefinitely, resulting in simplefb and other blocks that
> depend on its clocks to defer probe as well. Remove DSI PHY clocks from
> MMCC to let it probe with MDSS disabled.
> 

Isn't this a generic problem that we will have all over the place, where
we describe incoming clocks from all PHYs and then only enable the ones
actually available on each platform?

Am I missing something special with this case? I think the kernel need
to handle this.

Regards,
Bjorn

> Fixes: 48aa636285ad ("arm64: dts: qcom: msm8996: add clocks to the MMCC device node")
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> ---
>  .../boot/dts/qcom/msm8996pro-xiaomi-scorpio.dts     | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/msm8996pro-xiaomi-scorpio.dts b/arch/arm64/boot/dts/qcom/msm8996pro-xiaomi-scorpio.dts
> index 7bf6ad1a214b..c68c2dadd7b4 100644
> --- a/arch/arm64/boot/dts/qcom/msm8996pro-xiaomi-scorpio.dts
> +++ b/arch/arm64/boot/dts/qcom/msm8996pro-xiaomi-scorpio.dts
> @@ -113,6 +113,19 @@ &mdss {
>  	status = "disabled";
>  };
>  
> +&mmcc {
> +	/*
> +	 * Remove non-essential DSI PHY clocks to allow MMCC to probe
> +	 * with MDSS disabled.
> +	 */
> +	clocks = <&xo_board>,
> +		 <&gcc GCC_MMSS_NOC_CFG_AHB_CLK>,
> +		 <&gcc GPLL0>;
> +	clock-names = "xo",
> +		      "gcc_mmss_noc_cfg_ahb_clk",
> +		      "gpll0";
> +};
> +
>  &mss_pil {
>  	firmware-name = "qcom/msm8996/scorpio/mba.mbn",
>  			"qcom/msm8996/scorpio/modem.mbn";
> -- 
> 2.38.1
>