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References: <20230531-topic-8998_mmssclk-v1-0-2b5a8fc90991@linaro.org> <20230531-topic-8998_mmssclk-v1-4-2b5a8fc90991@linaro.org>
In-Reply-To: <20230531-topic-8998_mmssclk-v1-4-2b5a8fc90991@linaro.org>
From:   Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Date:   Thu, 1 Jun 2023 08:14:41 -0600
Message-ID: <CAOCk7Nogy3+5rvyzPEgsyJe7xE_17MXVs-=mniJJj=ELsCqzNQ@mail.gmail.com>
Subject: Re: [PATCH 4/4] clk: qcom: mmcc-msm8998: Fix the SMMU GDSC
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Imran Khan <kimran@codeaurora.org>,
        Rajendra Nayak <quic_rjendra@quicinc.com>,
        Joonwoo Park <joonwoop@codeaurora.org>,
        Jeffrey Hugo <jhugo@codeaurora.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Jami Kettunen <jami.kettunen@somainline.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
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On Wed, May 31, 2023 at 3:01=E2=80=AFAM Konrad Dybcio <konrad.dybcio@linaro=
.org> wrote:
>
> The SMMU GDSC doesn't have to be ALWAYS-ON and shouldn't feature the
> HW_CTRL flag (it's separate from hw_ctrl_addr).  In addition to that,
> it should feature a cxc entry for bimc_smmu_axi_clk and be marked as
> votable.
>
> Fix all of these issues.
>
> Fixes: d14b15b5931c ("clk: qcom: Add MSM8998 Multimedia Clock Controller =
(MMCC) driver")
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Was this tested on a system where the bootloader has enabled the
display and it is active during Linux boot?

I seem to recall that in that scenario, Linux would boot up, see that
the GDSC is on, not see any clients for it (still initializing), turn
it off, and kill the display which then results in either a mess of
errors or a bus lockup.

-Jeff