Re: [PATCH v2 1/5] thermal: change "hysteresis" as optional property

From: Leo Yan
Date: Sun Mar 20 2016 - 11:41:04 EST


Hi Javi,

Sorry for late response.

On Wed, Mar 09, 2016 at 11:10:52AM +0000, Javi Merino wrote:
> On Tue, Mar 08, 2016 at 12:55:59PM -0800, Eduardo Valentin wrote:
> > On Tue, Mar 08, 2016 at 09:57:43PM +0800, Leo Yan wrote:

[...]

> > > > > > > The property "hysteresis" is mandatory for trip points, so if without
> > > > > > > it the thermal zone cannot register successfully. But "hysteresis" is
> > > > > > > ignored in the thermal subsystem and only inquired by several thermal
> > > > > > > sensor drivers.
> > > > > >
> > > > > > If the Linux thermal subsystem has a problem with handling hysteresis, I
> > > > > > would rather fix Linux code than relaxing the DT binding. Or if you
> > > > > > still believe hysteresis is really optional, I would prefer to see a
> > > > > > better justification than "Linux ignores it".
> > > >
> > > > I see it the other way round, Is hysteresis a property that, without
> > > > it, the thermal code can't configure itself so it fails to create the
> > > > trip point? The current code goes "There is no hysteresis for this
> > > > property, I don't know how to set up this trip point!". I think we
> > > > can do better than this.
> > >
> > > Do you agree with Javi's suggestion? If you think it's okay, I will
> > > move on to send out a new version patch based on Javi's comments.
> >
> > No I don't. This discussion so far has been about Linux code. I still
> > havent seen an argument explaining why hysteresis has to be optional.
>
> Fair enough. Looks like I'm holding this driver from being
> upstreamed, so I'll back off.
>
> Leo, sorry for misguiding you. Please bring back the hysteresis
> property you had in v1.

Not at all. I will add back hysteresis property and resend new patches.

Thanks,
Leo Yan