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From:   Brian Masney <bmasney@redhat.com>
To:     andersson@kernel.org
Cc:     agross@kernel.org, konrad.dybcio@somainline.org,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, ahalaney@redhat.com,
        echanude@redhat.com
Subject: [PATCH v2] arm64: dts: qcom: sc8280xp: correct ref_aux clock for ufs_mem_phy
Date:   Thu, 25 Aug 2022 12:37:55 -0400
Message-Id: <20220825163755.683843-1-bmasney@redhat.com>
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The first UFS host controller fails to start on the SA8540P automotive
board (QDrive3) due to the following errors:

    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag_retry: query attribute, opcode 5, idn 18, failed
        with error 253 after 3 retries

The system eventually fails to boot with the warning:

    gcc_ufs_phy_axi_clk status stuck at 'off'

This issue can be worked around by adding clk_ignore_unused to the
kernel command line since the system firmware sets up this clock for us.

Let's fix this issue by updating the ref_aux clock on ufs_mem_phy. Note
that the downstream MSM 5.4 sources list this as ref_clk_parent. With
this patch, the SA8540P is able to be booted without clk_ignore_unused.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Fixes: 152d1faf1e2f3 ("arm64: dts: qcom: add SC8280XP platform")
---
v1 of this patch can be found at
https://lore.kernel.org/lkml/20220623142837.3140680-1-bmasney@redhat.com/T/#u

Note that there's also a similar issue with the second UFS controller
(ufs_card_hc) since it separately fails with:

    ufshcd-qcom 1da4000.ufs: Controller enable failed
    ufshcd-qcom 1da4000.ufs: link startup failed 1
    ...
    gcc_ufs_card_axi_clk status stuck at 'off'

We are currently disabling the second UFS host controller (ufs_card_hc) in
our DTS at the moment. I'm still looking through the downstream code to
try to track this particular issue down.

 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 49ea8b5612fc..4117ec0ffefc 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
@@ -892,7 +892,7 @@ ufs_mem_phy: phy@1d87000 {
 			clock-names = "ref",
 				      "ref_aux";
 			clocks = <&rpmhcc RPMH_CXO_CLK>,
-				 <&gcc GCC_UFS_PHY_PHY_AUX_CLK>;
+				 <&gcc GCC_UFS_REF_CLKREF_CLK>;
 
 			resets = <&ufs_mem_hc 0>;
 			reset-names = "ufsphy";
-- 
2.37.1