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Date:   Fri, 7 Oct 2022 21:29:41 +0200
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Subject: Re: [PATCH] arm64: dts: qcom: sc8280xp: fix ufs_card_phy ref clock
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To:     Johan Hovold <johan+linaro@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>
Cc:     Andy Gross <agross@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Brian Masney <bmasney@redhat.com>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20221005143305.388-1-johan+linaro@kernel.org>
From:   Konrad Dybcio <konrad.dybcio@somainline.org>
In-Reply-To: <20221005143305.388-1-johan+linaro@kernel.org>
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On 5.10.2022 16:33, Johan Hovold wrote:
> The GCC_UFS_REF_CLKREF_CLK must be enabled or the second UFS controller
> fails to enumerate on sa8295p-adp.
> 
> Note that the vendor kernel enables both GCC_UFS_REF_CLKREF_CLK and
> GCC_UFS_1_CARD_CLKREF_CLK and it is possible that the former should be
> modelled as a parent of the latter. The clock driver also has a
> GCC_UFS_CARD_CLKREF_CLK clock which the firmware appears to enable on
> the ADP.
My guess would be that XBL/whatever other bootloader enables all of them as
it scans for bootable devices and only gates one afterwards..


Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>

Konrad
> 
> The usual lack of documentation for Qualcomm SoCs makes this a highly
> annoying guessing game, but as the second controller works on the ADP
> without either card reference clock enabled, only enable
> GCC_UFS_REF_CLKREF_CLK for now.
> 
> Fixes: 152d1faf1e2f ("arm64: dts: qcom: add SC8280XP platform")
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
> 
> The related issue for the first controller is being fixed here:
> 
> 	https://lore.kernel.org/lkml/20220830180120.2082734-1-bmasney@redhat.com/T/#u
> 
> Johan
> 
> 
>  arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> index cf7ef37c11ec..917f1feac6ac 100644
> --- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> @@ -960,7 +960,7 @@ ufs_card_phy: phy@1da7000 {
>  			ranges;
>  			clock-names = "ref",
>  				      "ref_aux";
> -			clocks = <&gcc GCC_UFS_1_CARD_CLKREF_CLK>,
> +			clocks = <&gcc GCC_UFS_REF_CLKREF_CLK>,
>  				 <&gcc GCC_UFS_CARD_PHY_AUX_CLK>;
>  
>  			resets = <&ufs_card_hc 0>;