public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Tony Lindgren <tony@atomide.com>
To: Ravikumar <rk@ti.com>
Cc: "bcousson@baylibre.com" <bcousson@baylibre.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] ARM: dts: dra7: Reduce cpu thermal shutdown temperature
Date: Tue, 16 May 2017 09:28:17 -0700	[thread overview]
Message-ID: <20170516162816.GJ31418@atomide.com> (raw)
In-Reply-To: <e96e275d-1ba0-c904-e469-d86c6e687912@ti.com>

* Ravikumar <rk@ti.com> [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 <rk@ti.com>
> > ---
> >   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

      reply	other threads:[~2017-05-16 16:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-12  6:24 [PATCH 1/1] ARM: dts: dra7: Reduce cpu thermal shutdown temperature Ravikumar Kattekola
2017-05-03 13:57 ` Ravikumar
2017-05-16 16:28   ` Tony Lindgren [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170516162816.GJ31418@atomide.com \
    --to=tony@atomide.com \
    --cc=bcousson@baylibre.com \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=rk@ti.com \
    --cc=robh+dt@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox