Subject: [PATCH 1/1] ARM: dts: dra7: Reduce cpu thermal shutdown temperature

From: [email-masked] (Tony Lindgren)
Date: Tue, 16 May 2017 09:28:17 -0700

* Ravikumar <[email-masked]> [170503 06:57]:
> Hi,
> 
> On Wednesday 12 April 2017 11:54 AM, Kattekola, Ravikumar wrote:
> > On dra7, as per TRM, the HW shutdown (TSHUT) temperature is hardcoded
> > to 123C and cannot be modified by SW. This means when the temperature
> > reaches 123C HW asserts TSHUT output which signals a warm reset.
> > This reset is held until the temperature goes below the TSHUT low (105C).
> > 
> > While in SW, the thermal driver continuously monitors current temperature
> > and takes decisions based on whether it reached an alert or a critical point.
> > The intention of setting a SW critical point is to prevent force reset by HW
> > and instead do an orderly_poweroff(). But if the SW critical temperature is
> > greater than or equal to that of HW then it defeats the purpose. To address
> > this and let SW take action before HW does keep the SW critical temperature
> > less than HW TSHUT value.
> > 
> > The value for SW critical temperature was chosen as 120C just to ensure
> > we give SW sometime before HW catches up.
> > 
> > Document reference
> > SPRUI30C ? DRA75x, DRA74x Technical Reference Manual - November 2016
> > SPRUHZ6H - AM572x Technical Reference Manual - November 2016
> > 
> > Tested on:
> > DRA75x PG 2.0 Rev H EVM
> > 
> > Signed-off-by: Ravikumar Kattekola <[email-masked]>
> > ---
> >   arch/arm/boot/dts/dra7.dtsi | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
> > index 57892f2..e714466 100644
> > --- a/arch/arm/boot/dts/dra7.dtsi
> > +++ b/arch/arm/boot/dts/dra7.dtsi
> > @@ -2017,4 +2017,8 @@
> >   	coefficients = <0 2000>;
> >   };
> > +&cpu_crit {
> > +	temperature = <120000>; /* milli Celsius */
> > +};
> > +
> >   /include/ "dra7xx-clocks.dtsi"
> Ping..
> Any comments?

Seems good to have thanks. Applying into omap-for-v4.12/fixes.

Regards,

Tony