[RESEND PATCH v2 0/9] imx: thermal: Allow trip point configuration from DT

[Francesco Dolcini]

Hello Michal,

On Fri, Jun 17, 2022 at 10:36:17AM +0200, Michal Vokáč wrote:
> On 17. 06. 22 9:55, Francesco Dolcini wrote:
> > On Fri, Jun 17, 2022 at 07:51:53AM +0000, Jacky Bai wrote:
> > > > On Fri, Jun 17, 2022 at 07:31:25AM +0000, Jacky Bai wrote:
> > > > > > Subject: [RESEND PATCH v2 0/9] imx: thermal: Allow trip point
> > > > > > configuration from DT
> > > > > > 
> > > > > > This series allows to specify the imx thermal drivers trip point
> > > > > > from the device tree, without this change the threshold are
> > > > > > hard-coded and this might not be correct given the thermal design of the
> > > > final system.
> > > > > > 
> > > > > 
> > > > > The threshold is set dynamically based on the part market temp grade.
> > > > > I am little confused why need to specify it in DT?  I saw in 'PATCH
> > > > > 5/9', you provide a threshold table based temp grade, why not use the
> > > > > threshold from ' imx_init_temp_grade'?
> > > > 
> > > > The problem with the existing temperature thresholds is that they are
> > > > hard-coded into the driver, there is no way to change those to match the
> > > > actual final system thermal design.
> 
> AFAIK you can change the trip point from user space if you build
> with THERMAL_WRITABLE_TRIPS so in fact you can adapt it to the final
> system design.
> 
> We did exactly that when we swapped imx6 dual for imx6 quad but did not
> have enough space for adequate heat sink.

When I investigated this only the passive threshold was writeable from
user-space/sysfs, and Daniel was against any patch to allow changing
also the critical one [0].

Francesco

[0] https://lore.kernel.org/all/4de41b5e-1fa6-ece4-9d9a-2656d399b452@linaro.org/