[PATCH v1] imx: Fix critical thermal threshold

[Peng Fan]

> Subject: Re: [PATCH v1] imx: Fix critical thermal threshold
> 
> Hello Peng,
> 
> On Wed, Nov 13, 2024 at 09:10:46AM +0000, Peng Fan wrote:
> > > Subject: Re: [PATCH v1] imx: Fix critical thermal threshold On Wed,
> > > Nov 13, 2024 at 05:27:23AM +0000, Peng Fan wrote:
> > > > > Subject: [PATCH v1] imx: Fix critical thermal threshold
> > > > >
> > > > > From: Francesco Dolcini <francesco.dolcini at toradex.com>
> > > > >
> > > > > Fix the critical thermal threshold for i.MX processors, this was
> > > > > changed while moving the code from imx8m/imx9 directories
> into
> > > a
> > > > > shared place.
> > > > >
> > > > > There is no need to keep the critical threshold 5 degrees less
> > > > > than the SoC maximum temperature threshold, what is actually
> > > > > going to happen in practice is that we are going to power-off
> > > > > the board
> > > when
> > > > > the SoC is still within its working temperature range.
> > > >
> > > > Should we leave some margin for the critical temperature?
> > >
> > > What's the point of such a margin? For doing what?
> > >
> > > What is happening is that the OS takes some drastic measure when
> the
> > > critical threshold is reached, for example rebooting or shutting
> > > down the system. Why would I want to deliberately remove 5
> Celsius
> > > degrees of valid working temperature range from my SoC?
> >
> > The maxc means the maximum temperature that the soc might run
> at.
> > If the current temperature >= maxc, the chip might be broken.
> > And temperature sensor may have some deviation.
> > So leave margin for SW to shutdown the system.
> 
> Let's brake this problem in two.
> 
> 1. the change you did created a regression. this must be solved, and
> this patch
>    is solving it. after that we can discuss if this needs to be refined in any
> way,
>    for example making this threshold configurable in some way
> 
> 2. the device tree is supposed to describe the HW. This is the threshold
>    without any *arbitrary* margin. I need to be able to run my system
> at the
>    maximum allowed working temperature. If you want a policy to
> preserve some
>    margin this is not something that should be enforced this way. How
> can you
>    decide that 5 degrees are enough to be able to shutdown the system?
> It really
>    depends if the temperature is raising or not, how fast it is raising, and
> even
>    more external factors.

ok. Fair enough. I am fine with your change.

Regards,
Peng.

> 
> Francesco