From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 1/1] ARM: dts: dra7: Reduce cpu thermal shutdown temperature Date: Tue, 16 May 2017 09:28:17 -0700 Message-ID: <20170516162816.GJ31418@atomide.com> References: <20170412062442.17736-1-rk@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ravikumar Cc: "bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org" , "robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "mark.rutland-5wv7dgnIgG8@public.gmane.org" , "linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org * Ravikumar [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 > > --- > > 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html