From: Stephan Gerhold <stephan@gerhold.net>
To: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Bjorn Andersson <andersson@kernel.org>,
Andy Gross <agross@kernel.org>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Conor Dooley <conor+dt@kernel.org>,
Marijn Suijten <marijn.suijten@somainline.org>,
linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH 04/15] clk: qcom: gcc-sm6375: Add runtime PM
Date: Mon, 17 Jul 2023 18:26:35 +0200 [thread overview]
Message-ID: <ZLVru50N2ukdXnsW@gerhold.net> (raw)
In-Reply-To: <20230717-topic-branch_aon_cleanup-v1-4-27784d27a4f4@linaro.org>
On Mon, Jul 17, 2023 at 05:19:11PM +0200, Konrad Dybcio wrote:
> The GCC block on SM6375 is powered by the VDD_CX rail. We need to ensure
> that it's enabled to prevent unwanted power collapse.
>
> Enable runtime PM to keep the power flowing only when necessary.
>
Are you sure this is necessary? If VDD_CX was really possible to fully
"power collapse" then I would expect that you lose all register
settings. This is not something we want or can even handle for GCC.
You would need to restore all frequency settings, branch bits etc etc.
Otherwise it's a retention state, but these are covered by the
corners/levels, not the enable/disable state.
I think most of these power domains are effectively always-on. The
important part is voting for minimal corners/levels so they can go to
minimal retention state with vlow/vmin.
Thanks,
Stephan
next prev parent reply other threads:[~2023-07-17 16:26 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-17 15:19 [PATCH 00/15] Unregister critical branch clocks + some RPM Konrad Dybcio
2023-07-17 15:19 ` [PATCH 01/15] clk: qcom: branch: Add a helper for setting the enable bit Konrad Dybcio
2023-07-18 13:17 ` Johan Hovold
2023-07-17 15:19 ` [PATCH 02/15] clk: qcom: Use qcom_branch_set_clk_en() Konrad Dybcio
2023-07-18 13:18 ` Johan Hovold
2023-07-17 15:19 ` [PATCH 03/15] clk: qcom: gcc-sm6375: Unregister critical clocks Konrad Dybcio
2023-07-18 13:20 ` Johan Hovold
2023-07-18 13:26 ` Konrad Dybcio
2023-07-18 16:23 ` Bjorn Andersson
2023-07-19 8:43 ` Johan Hovold
2023-08-09 16:52 ` Konrad Dybcio
2023-09-01 17:55 ` Konrad Dybcio
2023-07-17 15:19 ` [PATCH 04/15] clk: qcom: gcc-sm6375: Add runtime PM Konrad Dybcio
2023-07-17 16:26 ` Stephan Gerhold [this message]
2023-07-18 4:02 ` Bjorn Andersson
2023-07-18 12:07 ` Stephan Gerhold
2023-07-18 12:49 ` Konrad Dybcio
2023-07-18 13:27 ` Johan Hovold
2023-07-17 15:19 ` [PATCH 05/15] clk: qcom: gpucc-sm6375: Unregister critical clocks Konrad Dybcio
2023-07-17 16:15 ` Stephan Gerhold
2023-07-17 16:17 ` Konrad Dybcio
2023-07-17 15:19 ` [PATCH 06/15] clk: qcom: gpucc-sm6115: " Konrad Dybcio
2023-07-17 15:19 ` [PATCH 07/15] clk: qcom: gpucc-sm6115: Add runtime PM Konrad Dybcio
2023-07-18 13:24 ` Johan Hovold
2023-07-18 13:28 ` Konrad Dybcio
2023-08-09 17:20 ` Konrad Dybcio
2023-07-17 15:19 ` [PATCH 08/15] clk: qcom: gcc-sm6115: Unregister critical clocks Konrad Dybcio
2023-07-17 15:19 ` [PATCH 09/15] clk: qcom: gcc-sm6115: Add runtime PM Konrad Dybcio
2023-07-17 15:19 ` [PATCH 10/15] clk: qcom: gcc-qcm2290: Unregister critical clocks Konrad Dybcio
2023-07-17 15:19 ` [PATCH 11/15] clk: qcom: gcc-qcm2290: Add runtime PM Konrad Dybcio
2023-07-17 15:19 ` [PATCH 12/15] arm64: dts: qcom: sm6375: Add VDD_CX to GCC Konrad Dybcio
2023-07-17 15:19 ` [PATCH 13/15] arm64: dts: qcom: qcm2290: " Konrad Dybcio
2023-07-17 15:19 ` [PATCH 14/15] arm64: dts: qcom: sm6115: " Konrad Dybcio
2023-07-17 15:19 ` [PATCH 15/15] arm64: dts: qcom: sm6115: Add VDD_CX to GPU_CCC Konrad Dybcio
2023-07-17 16:28 ` Stephan Gerhold
2023-07-17 16:50 ` Konrad Dybcio
2023-07-17 16:56 ` Stephan Gerhold
2023-07-17 17:11 ` Konrad Dybcio
2023-07-17 17:23 ` Stephan Gerhold
2023-07-17 19:18 ` Konrad Dybcio
2023-07-18 11:56 ` Stephan Gerhold
2023-07-18 12:47 ` Konrad Dybcio
2023-07-18 13:08 ` Dmitry Baryshkov
2023-07-18 13:36 ` Konrad Dybcio
2023-07-18 4:25 ` Bjorn Andersson
2023-07-18 12:21 ` Konrad Dybcio
2023-07-18 15:06 ` Bjorn Andersson
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