Re: [PATCH v1] thermal: imx: Make trip point offset configurable

[Francesco Dolcini <francesco.dolcini@toradex.com>]

On Mon, May 16, 2022 at 09:06:10PM +0200, Ahmad Fatoum wrote:
> On 16.05.22 21:00, Francesco Dolcini wrote:
> > Currently the imx thermal driver has a hardcoded critical temperature
> > value offset of 5 Celsius degrees from the actual SoC maximum
> > temperature.
> > 
> > This affects applications and systems designed to be working on this close
> > to the limit, but yet valid, temperature range.
> > 
> > Given that there is no single value that will fit all the use cases make
> > the critical trip point offset from the max temperature configurable
> > using a newly added trip_offset module parameter, passive trip point is
> > set to 5 Celsius degrees less than the critical. By default the
> > system behaves exactly as before.
> > 
> > Link: https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> >  drivers/thermal/imx_thermal.c | 12 ++++++++----
> >  1 file changed, 8 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> > index 16663373b682..42d1f8a3eccb 100644
> > --- a/drivers/thermal/imx_thermal.c
> > +++ b/drivers/thermal/imx_thermal.c
> > @@ -86,6 +86,10 @@ enum imx_thermal_trip {
> >  #define TEMPMON_IMX6SX			2
> >  #define TEMPMON_IMX7D			3
> >  
> > +static int trip_offset = 5;
> > +module_param(trip_offset, int, 0444);
> 
> Is this being r--r--r-- intended?

Yes, would you expect something more or less strict?

Daniel was pretty assertive that this is supposed to be a system
property and not something that should be possible to mess around with
[0]. Given this and that trip points are a+r in sysfs this was the most
reasonable solution to me. Said that I do not mind changing
this to 640 or 0440 or ...

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

Francesco