From: Neil Armstrong <neil.armstrong@linaro.org>
To: Akhil P Oommen <quic_akhilpo@quicinc.com>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konradybcio@kernel.org>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>
Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] arm64: dts: qcom: sm8650: setup gpu thermal with higher temperatures
Date: Mon, 13 Jan 2025 11:45:50 +0100 [thread overview]
Message-ID: <c09192f4-30ae-4dd8-bc88-2aaf02088374@linaro.org> (raw)
In-Reply-To: <8fc3b958-5c2f-4c79-8dc0-d1eec9f5e47d@quicinc.com>
Hi,
On 13/01/2025 11:28, Akhil P Oommen wrote:
> On 1/10/2025 4:06 PM, Neil Armstrong wrote:
>> On the SM8650, the dynamic clock and voltage scaling (DCVS) for the GPU
>> is done in an hardware controlled loop by the GPU Management Unit (GMU).
>>
>> Since the GMU does a better job at maintaining the GPUs temperature in an
>> acceptable range by taking in account more parameters like the die
>> characteristics or other internal sensors, it makes no sense to try
>> and reproduce a similar set of constraints with the Linux devfreq thermal
>> core.
>
> Just FYI, this description is incorrect. SM8650's GMU doesn't do any
> sort of thermal management.
Ok, thx for confirming this, in our tests the temperature steadily stayed
at a max trip point when setting them higher. But perhaps it's a side effect
of other mitigations.
Are the new trip points still ok ? they are derived from the downstream DT.
Thanks,
Neil
>
> -Akhil.
>
>>
>> Instead, set higher temperatures in the GPU trip points corresponding to
>> the temperatures provided by Qualcomm in the dowstream source, which will
>> trigger the devfreq thermal core if the GMU cannot handle the temperature
>> surge, and try our best to avoid reaching the critical temperature trip
>> point which should trigger an inevitable thermal shutdown.
>>
>> Fixes: 497624ed5506 ("arm64: dts: qcom: sm8650: Throttle the GPU when overheating")
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>> arch/arm64/boot/dts/qcom/sm8650.dtsi | 48 ++++++++++++++++++------------------
>> 1 file changed, 24 insertions(+), 24 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sm8650.dtsi b/arch/arm64/boot/dts/qcom/sm8650.dtsi
>> index 95509ce2713d4fcc3dbe0c5cd5827312d5681af4..e9fcf05cb084b7979ecf0f4712fed332e9f4b07a 100644
>> --- a/arch/arm64/boot/dts/qcom/sm8650.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/sm8650.dtsi
>> @@ -6173,19 +6173,19 @@ map0 {
>>
>> trips {
>> gpu0_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6206,19 +6206,19 @@ map0 {
>>
>> trips {
>> gpu1_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6239,19 +6239,19 @@ map0 {
>>
>> trips {
>> gpu2_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6272,19 +6272,19 @@ map0 {
>>
>> trips {
>> gpu3_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6305,19 +6305,19 @@ map0 {
>>
>> trips {
>> gpu4_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6338,19 +6338,19 @@ map0 {
>>
>> trips {
>> gpu5_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6371,19 +6371,19 @@ map0 {
>>
>> trips {
>> gpu6_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>> @@ -6404,19 +6404,19 @@ map0 {
>>
>> trips {
>> gpu7_alert0: trip-point0 {
>> - temperature = <85000>;
>> + temperature = <95000>;
>> hysteresis = <1000>;
>> type = "passive";
>> };
>>
>> trip-point1 {
>> - temperature = <90000>;
>> + temperature = <115000>;
>> hysteresis = <1000>;
>> type = "hot";
>> };
>>
>> trip-point2 {
>> - temperature = <110000>;
>> + temperature = <125000>;
>> hysteresis = <1000>;
>> type = "critical";
>> };
>>
>
next prev parent reply other threads:[~2025-01-13 10:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-10 10:36 [PATCH v2 0/2] arm64: dts: qcom: sm8650: rework CPU & GPU thermal zones Neil Armstrong
2025-01-10 10:36 ` [PATCH v2 1/2] arm64: dts: qcom: sm8650: drop cpu thermal passive trip points Neil Armstrong
2025-01-10 10:36 ` [PATCH v2 2/2] arm64: dts: qcom: sm8650: setup gpu thermal with higher temperatures Neil Armstrong
2025-01-13 10:28 ` Akhil P Oommen
2025-01-13 10:45 ` Neil Armstrong [this message]
2025-01-15 19:09 ` Akhil P Oommen
2025-01-16 21:20 ` Konrad Dybcio
2025-01-22 14:09 ` Akhil P Oommen
2025-01-23 11:59 ` Konrad Dybcio
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