Re: [PATCH v7 9/9] arm64: dts: qcom: hamoa: Enable CDSP cooling

Gaurav Kohli <[email protected]> Fri, 31 Jul 2026 18:52:24 +0530
Newsgroups org.kernel.vger.linux-remoteproc,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-hardening,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pm
Message-ID <[email protected]>

On 7/31/2026 4:50 PM, Stephan Gerhold wrote:
> On Fri, Jul 31, 2026 at 04:03:49PM +0530, Gaurav Kohli wrote:
>> From: Dipa Ramesh Mantre <[email protected]>
>>
>> Unlike the CPU, the CDSP does not throttle its speed automatically
>> when it reaches high temperatures in hamoa.
>>
>> Set up CDSP cooling by throttling the cdsp, when it reaches 95°C.
>>
>> Add polling-delay-passive so the governor periodically evaluates
>> the zone during passive cooling and steps up cooling levels when
>> temperature stabilizes below the next trip.
>>
> 
> Would be good to mention why you are treating hamoa-iot-evk differently.

thanks for review, will add the reasoning.

> 
>> Signed-off-by: Dipa Ramesh Mantre <[email protected]>
>> Reviewed-by: Dmitry Baryshkov <[email protected]>
>> Signed-off-by: Gaurav Kohli <[email protected]>
>> ---
>>   arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts | 32 +++++++++++++++
>>   arch/arm64/boot/dts/qcom/hamoa.dtsi        | 63 ++++++++++++++++++++++++++++++
>>   2 files changed, 95 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
>> index 9fa86bb6438e..a146be1cb5fb 100644
>> --- a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
>> +++ b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
>> @@ -1684,4 +1684,36 @@ trip-point0 {
>>   			};
>>   		};
>>   	};
>> +
>> +	nsp0-thermal {
>> +		trips {
>> +			trip-point1 {
>> +				temperature = <105000>;
>> +			};
>> +		};
>> +	};
>> +
>> +	nsp1-thermal {
>> +		trips {
>> +			trip-point1 {
>> +				temperature = <105000>;
>> +			};
>> +		};
>> +	};
>> +
>> +	nsp2-thermal {
>> +		trips {
>> +			trip-point1 {
>> +				temperature = <105000>;
>> +			};
>> +		};
>> +	};
>> +
>> +	nsp3-thermal {
>> +		trips {
>> +			trip-point1 {
>> +				temperature = <105000>;
>> +			};
>> +		};
>> +	};
>>   };
> 
> Please avoid overriding node values like this... One quick rename of one
> of the involved nodes and this will be silently broken without compile
> error. Nowadays dtbs_check will *probably* catch these, but if you
> override values using the label reference you would notice it
> immediately when compiling.
> 
> All those nodes already have a label you can use:
> 
> &nsp0_alert0 {
> 	temperature = <105000>;
> };
> 
> &nsp1_alert0 {
> 	temperature = <105000>;
> };
> 
> If the same pattern is already used for other thermal overrides in
> hamoa-iot-evk.dts, it would be good to prepend a patch to fix those too.

thanks for review, will update this.

> 
> Thanks,
> Stephan