From: Akhil P Oommen <quic_akhilpo@quicinc.com>
To: Bjorn Andersson <andersson@kernel.org>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: David Airlie <airlied@linux.ie>,
Michael Turquette <mturquette@baylibre.com>,
Konrad Dybcio <konrad.dybcio@somainline.org>,
<dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
<linux-clk@vger.kernel.org>, Rob Clark <robdclark@gmail.com>,
Andy Gross <agross@kernel.org>, <devicetree@vger.kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
<linux-arm-msm@vger.kernel.org>,
Abhinav Kumar <quic_abhinavk@quicinc.com>,
Stephen Boyd <swboyd@chromium.org>,
Rob Herring <robh+dt@kernel.org>, "Sean Paul" <sean@poorly.run>,
Stephen Boyd <sboyd@kernel.org>,
Douglas Anderson <dianders@chromium.org>,
<krzysztof.kozlowski@linaro.org>, Daniel Vetter <daniel@ffwll.ch>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
freedreno <freedreno@lists.freedesktop.org>
Subject: Re: [Freedreno] [PATCH v7 0/6] clk/qcom: Support gdsc collapse polling using 'reset' interface
Date: Fri, 2 Dec 2022 12:30:43 +0530 [thread overview]
Message-ID: <a0544298-f463-4994-1cf4-9e290f85bf37@quicinc.com> (raw)
In-Reply-To: <20221201225705.46r2m35ketvzipox@builder.lan>
On 12/2/2022 4:27 AM, Bjorn Andersson wrote:
> On Wed, Oct 05, 2022 at 02:36:58PM +0530, Akhil P Oommen wrote:
> @Ulf, Akhil has a power-domain for a piece of hardware which may be
> voted active by multiple different subsystems (co-processors/execution
> contexts) in the system.
>
> As such, during the powering down sequence we don't wait for the
> power-domain to turn off. But in the event of an error, the recovery
> mechanism relies on waiting for the hardware to settle in a powered off
> state.
>
> The proposal here is to use the reset framework to wait for this state
> to be reached, before continuing with the recovery mechanism in the
> client driver.
>
> Given our other discussions on quirky behavior, do you have any
> input/suggestions on this?
>
>> Some clients like adreno gpu driver would like to ensure that its gdsc
>> is collapsed at hardware during a gpu reset sequence. This is because it
>> has a votable gdsc which could be ON due to a vote from another subsystem
>> like tz, hyp etc or due to an internal hardware signal. To allow
>> this, gpucc driver can expose an interface to the client driver using
>> reset framework. Using this the client driver can trigger a polling within
>> the gdsc driver.
> @Akhil, this description is fairly generic. As we've reached the state
> where the hardware has settled and we return to the client, what
> prevents it from being powered up again?
>
> Or is it simply a question of it hitting the powered-off state, not
> necessarily staying there?
Correct. It doesn't need to stay there. The intention is to hit the powered-off state at least once to clear all the internal hw states (basically a hw reset).
-Akhil.
>
> Regards,
> Bjorn
>
>> This series is rebased on top of qcom/linux:for-next branch.
>>
>> Related discussion: https://patchwork.freedesktop.org/patch/493144/
>>
>> Changes in v7:
>> - Update commit message (Bjorn)
>> - Rebased on top of qcom/linux:for-next branch.
>>
>> Changes in v6:
>> - No code changes in this version. Just captured the Acked-by tags
>>
>> Changes in v5:
>> - Nit: Remove a duplicate blank line (Krzysztof)
>>
>> Changes in v4:
>> - Update gpu dt-binding schema
>> - Typo fix in commit text
>>
>> Changes in v3:
>> - Use pointer to const for "struct qcom_reset_ops" in qcom_reset_map (Krzysztof)
>>
>> Changes in v2:
>> - Return error when a particular custom reset op is not implemented. (Dmitry)
>>
>> Akhil P Oommen (6):
>> dt-bindings: clk: qcom: Support gpu cx gdsc reset
>> clk: qcom: Allow custom reset ops
>> clk: qcom: gdsc: Add a reset op to poll gdsc collapse
>> clk: qcom: gpucc-sc7280: Add cx collapse reset support
>> dt-bindings: drm/msm/gpu: Add optional resets
>> arm64: dts: qcom: sc7280: Add Reset support for gpu
>>
>> .../devicetree/bindings/display/msm/gpu.yaml | 6 +++++
>> arch/arm64/boot/dts/qcom/sc7280.dtsi | 3 +++
>> drivers/clk/qcom/gdsc.c | 23 ++++++++++++++----
>> drivers/clk/qcom/gdsc.h | 7 ++++++
>> drivers/clk/qcom/gpucc-sc7280.c | 10 ++++++++
>> drivers/clk/qcom/reset.c | 27 +++++++++++++++++++++-
>> drivers/clk/qcom/reset.h | 8 +++++++
>> include/dt-bindings/clock/qcom,gpucc-sc7280.h | 3 +++
>> 8 files changed, 82 insertions(+), 5 deletions(-)
>>
>> --
>> 2.7.4
>>
next prev parent reply other threads:[~2022-12-02 7:01 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-05 9:06 [PATCH v7 0/6] clk/qcom: Support gdsc collapse polling using 'reset' interface Akhil P Oommen
2022-10-05 9:06 ` [PATCH v7 1/6] dt-bindings: clk: qcom: Support gpu cx gdsc reset Akhil P Oommen
2022-10-05 9:07 ` [PATCH v7 2/6] clk: qcom: Allow custom reset ops Akhil P Oommen
2022-10-05 9:07 ` [PATCH v7 3/6] clk: qcom: gdsc: Add a reset op to poll gdsc collapse Akhil P Oommen
2022-12-07 15:45 ` Ulf Hansson
2022-12-08 15:02 ` Akhil P Oommen
2022-12-08 15:30 ` [Freedreno] " Akhil P Oommen
2022-10-05 9:07 ` [PATCH v7 4/6] clk: qcom: gpucc-sc7280: Add cx collapse reset support Akhil P Oommen
2022-12-07 15:46 ` Ulf Hansson
2022-12-08 15:24 ` Akhil P Oommen
2022-12-08 21:09 ` Bjorn Andersson
2022-12-12 17:49 ` Akhil P Oommen
2022-10-05 9:07 ` [PATCH v7 5/6] dt-bindings: drm/msm/gpu: Add optional resets Akhil P Oommen
2022-10-05 9:07 ` [PATCH v7 6/6] arm64: dts: qcom: sc7280: Add Reset support for gpu Akhil P Oommen
2022-11-07 16:54 ` [PATCH v7 0/6] clk/qcom: Support gdsc collapse polling using 'reset' interface Akhil P Oommen
2022-12-01 22:57 ` Bjorn Andersson
2022-12-02 7:00 ` Akhil P Oommen [this message]
2022-12-06 19:58 ` [Freedreno] " Akhil P Oommen
2022-12-07 16:00 ` Ulf Hansson
2022-12-07 16:54 ` Bjorn Andersson
2022-12-08 13:40 ` Ulf Hansson
2022-12-08 14:45 ` Akhil P Oommen
2022-12-08 21:06 ` Bjorn Andersson
2022-12-09 17:36 ` Ulf Hansson
2022-12-12 15:39 ` Ulf Hansson
2022-12-12 17:43 ` Akhil P Oommen
2022-12-27 18:24 ` Bjorn Andersson
2022-12-28 9:23 ` Akhil P Oommen
2022-12-08 15:31 ` Akhil P Oommen
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