Re: [linux-sunxi] [PATCH 3/7] arm64: dts: allwinner: h6: set thermal polling time

[OndÅej Jirman]

Hello,

On Sun, Apr 05, 2020 at 12:49:09PM +0200, Clément Péron wrote:
> Add reasonable thermal polling time for Allwinner H6.
> 
> Signed-off-by: Clément Péron <peron.clem@xxxxxxxxx>
> ---
>  arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> index d4d3963705f5..c3e4f09f60ce 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> @@ -905,8 +905,8 @@
>  
>  	thermal-zones {
>  		cpu-thermal {
> -			polling-delay-passive = <0>;
> -			polling-delay = <0>;
> +			polling-delay-passive = <100>;
> +			polling-delay = <1000>;
>  			thermal-sensors = <&ths 0>;

This is not necessary, and will not do anything useful, since the driver
uses interrupts to update the thermal zone's temperature. Please keep the
values at 0.

With your settings the thermal zone would just add a polling timer in addition
to being updated every 250ms via THS interrupt. The real thermal measurements
are available every 250ms anyway, so setting a smaller period here will not do
anything useful, and 1s period will not lead to slower updates either.

Values of 0 mean tell the thermal zone to rely on thermal driver to update
the thermal zone by itself (via interrupt) and to not poll.

regards,
	o.

>  			trips {
> @@ -935,8 +935,8 @@
>  		};
>  
>  		gpu-thermal {
> -			polling-delay-passive = <0>;
> -			polling-delay = <0>;
> +			polling-delay-passive = <100>;
> +			polling-delay = <1000>;
>  			thermal-sensors = <&ths 1>;
>  		};
>  	};
> -- 
> 2.20.1
> 
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