Re: [PATCH v13 4/5] ARM: dts: add main Thermal info to rk3288

[Caesar Wang]

å 2014/10/24 9:37, Dmitry Torokhov åé:
> On October 23, 2014 6:08:52 PM PDT, Caesar Wang <caesar.wang@xxxxxxxxxxxxxx> wrote:
> > Dmitry,
> >
> > å 2014/10/24 8:46, Dmitry Torokhov åé:
> > > Hi Caesar,
> > >
> > > On Thu, Oct 23, 2014 at 05:40:06PM +0800, Caesar Wang wrote:
> > > > This patch is depend on rk3288-thermal.dtsi,or
> > > > it will compile error.
> > > >
> > > > If the temperature over a period of time High,over 120C
> > > > the resulting TSHUT gave CRU module,let it reset
> > > > the entire chip,or via GPIO give PMIC.
> > > >
> > > > Signed-off-by: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx>
> > > > ---
> > > >    arch/arm/boot/dts/rk3288.dtsi | 21 +++++++++++++++++++++
> > > >    1 file changed, 21 insertions(+)
> > > >
> > > > diff --git a/arch/arm/boot/dts/rk3288.dtsi
> > b/arch/arm/boot/dts/rk3288.dtsi
> > > > index cb18bb4..85fc17a 100644
> > > > --- a/arch/arm/boot/dts/rk3288.dtsi
> > > > +++ b/arch/arm/boot/dts/rk3288.dtsi
> > > > @@ -15,6 +15,7 @@
> > > >    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > >    #include <dt-bindings/pinctrl/rockchip.h>
> > > >    #include <dt-bindings/clock/rk3288-cru.h>
> > > > +#include <dt-bindings/thermal/thermal.h>
> > > >    #include "skeleton.dtsi"
> > > >    
> > > >    / {
> > > > @@ -66,6 +67,7 @@
> > > >    				 216000  900000
> > > >    				 126000  900000
> > > >    			>;
> > > > +			#cooling-cells = <2>; /* min followed by max */
> > > >    			clock-latency = <40000>;
> > > >    			clocks = <&cru ARMCLK>;
> > > >    		};
> > > > @@ -346,6 +348,19 @@
> > > >    		status = "disabled";
> > > >    	};
> > > >    
> > > > +	tsadc: tsadc@ff280000 {
> > > > +		compatible = "rockchip,rk3288-tsadc";
> > > > +		reg = <0xff280000 0x100>;
> > > > +		interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
> > > > +		clocks = <&cru SCLK_TSADC>, <&cru PCLK_TSADC>;
> > > > +		clock-names = "tsadc", "apb_pclk";
> > > > +		pinctrl-names = "default";
> > > > +		pinctrl-0 = <&otp_out>;
> > > > +		#thermal-sensor-cells = <1>;
> > > > +		hw-shut-temp = <120000>;
> > > I do not think this is a good value. You have (in the other DTS file)
> > > passive trip point at 80 and critical (which should result in orderly
> > > shutdown) at 125. But here you define hardware-controlled shutdown at
> > > 120C, which is backwards. You should have:
> > >
> > > passive <= critical <= hardware
> > Hmmm....
> > but, the system will shutdown when temperature over critial value,
> > there is no chance of triggering the TSHUT.
> >
> > If the temperature over a period of time High,as we know,
> > the resulting TSHUT gave CRU module,let it hot-reset the entire chip,
> > or via GPIO give PMIC cold-reset the entire chip.
> Having tshut trigger is not the goal, tshut is the measure of last resort. If we can handle thermal conditions without triggering tshut, we achieved our goal.
>
> Tshut triggering is " oh, crap, nothing we tried works" scenario.

I don't think so.

In general,We should have:
passive <= hardware(reset entire chip) <= critical(shutdown)

The temperature be rising qulckly if have some other conditions,
the "critical" will play a role.

Agreed?


> Thanks.

--
Best regards,
Caesar


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