Re: [PATCH/RFT] arm64: dts: renesas: r8a7795: Create thermal zone to support IPA

From: "Niklas Söderlund" <niklas.soderlund@ragnatech.se>
To: Simon Horman <horms@verge.net.au>
Cc: Yoshihiro Kaneko <ykaneko0929@gmail.com>,
	linux-renesas-soc@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Magnus Damm <magnus.damm@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH/RFT] arm64: dts: renesas: r8a7795: Create thermal zone to support IPA
Date: Thu, 11 Apr 2019 18:47:25 +0200	[thread overview]
Message-ID: <20190411164725.GE30887@bigcity.dyn.berto.se> (raw)
In-Reply-To: <20190408122941.wziujh5ibgwy5cdp@verge.net.au>

Hi Simon,

On 2019-04-08 14:29:41 +0200, Simon Horman wrote:
> > > @@ -3172,11 +3158,15 @@
> > >  
> > >  			cooling-maps {
> > >  				map0 {
> > > -					trip = <&sensor3_passive>;
> > > -					cooling-device = <&a57_0 4 4>,
> > > -							 <&a57_1 4 4>,
> > > -							 <&a57_2 4 4>,
> > > -							 <&a57_3 4 4>;
> > > +					trip = <&target>;
> > > +					cooling-device = <&a57_0 0 2>;
> > 
> > We have 5 (0-4) cooling states for the A57s on this SoC. Out of 
> > curiosity why allow states 0-2 here and not force it do more cooling or 
> > keep the to max cooling (4) as before this change as this is set to a 
> > trip point with a rather large temperature? Not saying this is wrong 
> > only curious :-)
> 
> This I do not know. Do you think it would be worth following-up on
> internally?

I'm no expert on this but I think it could be educational to learn why 
not the full range is used. Still this might be correct so I don't want 
to block this patch based on my ignorance.

-- 
Regards,
Niklas Söderlund