Re: [PATCH v1 00/12] qcom: dts: thermal cleanups
From: Eduardo Valentin
Date: Wed Feb 20 2019 - 18:33:06 EST
On Wed, Feb 20, 2019 at 03:09:36PM +0530, Amit Kucheria wrote:
> On Wed, Feb 20, 2019 at 6:56 AM Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
> > Hey
> > On Mon, Feb 18, 2019 at 06:05:14PM +0530, Amit Kucheria wrote:
> > > - Expose all temperature sensors on msm8916, msm996, msm8998, sdm845
> > > - split up the register address map for msm8998
> > > - standardize names of the various thermal-zones across boards to make it
> > > easy for test scripts to parse
> > >
> > I am generally fine with the effort but please fix the following
> > (applies for the whole series) wrt to required properties for DT
> > thermal:
> > a. Trip points for your zones
> Thanks for the review.
> In some cases, the temperatures are just exposed so something in
> userspace might read it and do something with it. We don't expect
> kernel trips for them.
Would a hwmon driver make more sense here?
> Adding trip points also requires me to add cooling-maps (your point b. below).
> I guess I'm looking for an example of how to just expose sensor
> temperatures w/o any associated trips and cooling maps.
> > b. Cooling Mappings for zones that have passive trips.
> From what I can see currently only CPUs and GPUs (among the major heat
> sources) can passively reduce heat by reducing frequencies.
> Things like cameras, display, video might have a more ON/OFF approach
> to throttling that might be controlled from userspace. And we don't
> have a way to tell in DT that these zones are managed in userspace
You can always add a Hot trip point. To my understanding that is for