Re: [PATCH 1/2] arm64: dts: rockchip: Fix multiple thermal zones conflict in rk3399.dtsi

From: Robin Murphy <robin.murphy@arm.com>
To: Heiko Stuebner <heiko@sntech.de>,
	Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org, edubezval@gmail.com,
	manivannan.sadhasivam@linaro.org,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Philipp Tomsich <philipp.tomsich@theobroma-systems.com>,
	Christoph Muellner <christoph.muellner@theobroma-systems.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Enric Balletbo i Serra <enric.balletbo@collabora.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Randy Li <ayaka@soulik.info>, Tony Xie <tony.xie@rock-chips.com>,
	Vicente Bergas <vicencb@gmail.com>,
	Klaus Goger <klaus.goger@theobroma-systems.com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"moderated list:ARM/Rockchip SoC support"
	<linux-arm-kernel@lists.infr>
Subject: Re: [PATCH 1/2] arm64: dts: rockchip: Fix multiple thermal zones conflict in rk3399.dtsi
Date: Fri, 14 Jun 2019 11:09:27 +0100	[thread overview]
Message-ID: <3ee47d34-bf71-9e53-9387-7407865d3110@arm.com> (raw)
In-Reply-To: <5188064.YWmxIpmbGp@phil>

On 14/06/2019 10:35, Heiko Stuebner wrote:
> Hi Daniel,
> 
> Am Dienstag, 4. Juni 2019, 18:57:57 CEST schrieb Daniel Lezcano:
>> Currently the common thermal zones definitions for the rk3399 assumes
>> multiple thermal zones are supported by the governors. This is not the
>> case and each thermal zone has its own governor instance acting
>> individually without collaboration with other governors.
>>
>> As the cooling device for the CPU and the GPU thermal zones is the
>> same, each governors take different decisions for the same cooling
>> device leading to conflicting instructions and an erratic behavior.
>>
>> As the cooling-maps is about to become an optional property, let's
>> remove the cpu cooling device map from the GPU thermal zone.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>> ---
>>   arch/arm64/boot/dts/rockchip/rk3399.dtsi | 9 ---------
>>   1 file changed, 9 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
>> index 196ac9b78076..e1357e0f60f7 100644
>> --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
>> +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
>> @@ -821,15 +821,6 @@
>>   					type = "critical";
>>   				};
>>   			};
>> -
>> -			cooling-maps {
>> -				map0 {
>> -					trip = <&gpu_alert0>;
>> -					cooling-device =
>> -						<&cpu_b0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
>> -						<&cpu_b1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
>> -				};
>> -			};
>>   		};
>>   	};
> 
> my knowledge of the thermal framework is not that big, but what about the
> rk3399-devices which further detail the cooling-maps like rk3399-gru-kevin
> and the rk3399-nanopc-t4 with its fan-handling in the cooling-maps?

FWIW, my knowledge of thermal is probably even less :)

For NanoPC-T4 I think I more or less just took Odroid-XU3/4 as the best 
pwm-fan example and adapted that into the existing RK3399 zones in the 
manner which seemed most logical to my interpretation - if what was 
there wasn't right to begin with, then I may well have done that wrong too.

Robin.