Re: [PATCH v2 5/5] ARM: tegra: Add thermal reset (thermtrip) support to PMC

[Mikko Perttunen]

On 21/08/14 18:40, Stephen Warren wrote:
> On 08/21/2014 07:11 AM, Mikko Perttunen wrote:
> > On 20/08/14 23:25, Stephen Warren wrote:
> > > On 08/13/2014 06:41 AM, Mikko Perttunen wrote:
> > > > This adds a device tree controlled option to enable PMC-based
> > > > thermal reset in overheating situations. Thermtrip is supported on
> > > > Tegra30, Tegra114 and Tegra124. The thermal reset only works when
> > > > the thermal sensors are calibrated, so a soctherm driver is also
> > > > required.
> > >
> > > If calibration is required, presumably the soctherm must initialize
> > > before this thermtrip code can initialize, or this thermtrip logic might
> > > be triggered by uncalibrated sensors?
> >
> > SOCTHERM requires that each sensor be explicitly enabled before it gives
> > readings. If a sensor is not enabled, the temperature given by the
> > register (and used to trigger thermtrip) will be zero. So in order for a
> > thermtrip shutdown to be caused before soctherm is initialized, the
> > thermtrip temperature would have to be programmed to below zero (the
> > default value is 105C), in which case an immediate shutdown would
> > probably be in order anyway (unless the user uses LN2 or something to
> > cool the soc below zero).
> >
> > > If so, then there needs to be some explicit mechanism to force the two
> > > drivers into probing in the right order.
> >
> > Because of the above, I think it isn't necessary to probe these in order.
>
> OK, that makes sense. Briefly mentioning this in the commit description
> could be useful.

Sure, I'll add a mention to the next version.

Mikko
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