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

[ClÃment PÃron]

Hi OndÅej,

On Sun, 5 Apr 2020 at 13:24, OndÅej Jirman <megous@xxxxxxxxxx> wrote:
>
> Hello,
>
> On Sun, Apr 05, 2020 at 12:49:09PM +0200, ClÃment PÃron wrote:
> > Add reasonable thermal polling time for Allwinner H6.
> >
> > Signed-off-by: ClÃment PÃron <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.

Thanks for the explanations,
I will drop this patch.

Regards,
ClÃment
>
> 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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