On Thu, May 30, 2019 at 02:27:28PM +0800, Hsin-Yi Wang wrote:
> On Fri, May 10, 2019 at 9:27 PM michael.kao <michael.kao@xxxxxxxxxxxx> wrote:
>
> > +
> > + tzts1: tzts1 {
> > + polling-delay-passive = <0>;
> > + polling-delay = <0>;
> > + thermal-sensors = <&thermal 1>;
> > + sustainable-power = <0>;
> > + trips {};
> > + cooling-maps {};
> > + };
> > +
> Is 0 a valid initial sustainable-power setting? Since we'll still get
> warning[1] about this, though it might not be harmful.
>
> If 0 is a valid setting, maybe we should consider showing the warning
> of not setting this property in [2]?
>
> [1] https://elixir.bootlin.com/linux/latest/source/drivers/thermal/power_allocator.c#L570
> [2] https://elixir.bootlin.com/linux/latest/source/drivers/thermal/of-thermal.c#L1049
IIUC a value of 0 is pointless, the thermal framework will still use
an estimated value:
https://elixir.bootlin.com/linux/v5.1.5/source/drivers/thermal/power_allocator.c#L203
As commented on v1 (https://patchwork.kernel.org/patch/10926519/#22620905)
the value of the property may depend on the thermal characteristics of
the device, there is not one correct value per SoC/core. If it is
specified at SoC level device makers should be aware that they might
have to override it for 'optimal' behavior on their device.
