Terve Mikko, On Mon, Feb 16, 2015 at 03:01:25PM +0200, Mikko Perttunen wrote: > On 02/09/2015 11:34 PM, Eduardo Valentin wrote: > > This change introduces a section in the Introduction Chapter to > > list concepts used by the Thermal Framework. > > > > Signed-off-by: Eduardo Valentin > > --- > > Documentation/DocBook/thermal.tmpl | 129 ++++++++++++++++++++++++++++++++++++- > > 1 file changed, 128 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/DocBook/thermal.tmpl b/Documentation/DocBook/thermal.tmpl > > index f8fb8a2..66efed3 100644 > > --- a/Documentation/DocBook/thermal.tmpl > > +++ b/Documentation/DocBook/thermal.tmpl > > @@ -84,5 +84,132 @@ > > devices. > > > > > > - > > + > > + Glossary > > + The Linux Kernel Thermal Framework uses a > > + specific terminology to represent the entities involved > > + in thermal constrained environments. This section > > + summaries the terminology as dictionary. These terms are > > + in use within the present document and in the source > > + code of the Linux Kernel Thermal Framework. > > + > > + > > + > > + Thermal Zone > > + > > + Thermal zones represent > > + what is the current status of a > > + thermal constrained zone in the > > + hardware. The zone usually is a > > + device or component. The status > > + of a thermal zone is mainly with > > + respect to temperature. > > + Currently, the Linux Kernel > > + Thermal Framework represents > > + temperature in miliCelsius. The > > milli-Celsius or millicelsius. Same change later too. OK. I will standardize. > > > + current abstraction covers for > > + non negative temperatures and > > + constraints. > > + > > + > > + > > + > > + Thermal Sensors > > + > > + Thermal sensors provide > > + temperature sensing capabilities > > + on thermal zones. Typical > > + devices are I2C ADC converters > > + and bandgaps. These are nodes > > + providing temperature data to > > + thermal zones. Thermal sensor > > + devices may control one or more > > + internal sensors. > > + > > + > > + > > + > > + Trips Points > > + > > + The trip node describes a > > + point in the temperature domain > > + in which the system takes an > > + action. This item describes just > > + the point, not the action. Trip > > + points are represented as > > + temperature in miliCelsius. The > > here > > > + current abstraction covers for > > + non negative temperatures. > > One thing I'd also like to see documented is the roles of the different > trip types (PASSIVE, ACTIVE, HOT, CRITICAL) and when each should be used. OK. That makes sense to me. I will include either a chapter about thermal zones and have a section about it, or include in here, in the glossary. I will think about it. Thanks for your thoughts! > > > + > > + > > + > > + > > + Thermal Governor > > + > > + Thermal Governors > > + represent a policy to manage the > > + thermal zone device temperature. > > + The governor targets to keep > > + temperature in an acceptable > > + range which correlates to the > > + power budget, while maximizing > > + the performance. Governors can > > + be implemented in Kernel Space > > + or in User Space. > > + > > + > > + > > + > > + Thermal Cooling Device > > + > > + Cooling devices provide > > + control on power dissipation. > > + There are essentially two ways > > + to provide control on power > > + dissipation. First is by means > > + of regulating device > > + performance, which is known as > > + passive cooling. A typical > > + passive cooling is a CPU that > > + has dynamic voltage and > > + frequency scaling (DVFS), and > > + uses lower frequencies as > > + cooling states. Second is by > > + means of activating devices in > > + order to remove the dissipated > > + heat, which is known as active > > + cooling, e.g. regulating fan > > + speeds. In both cases, cooling > > + devices shall have a way to > > + determine the state of cooling > > + in which the device is. > > + > > + > > + > > + > > + Cooling State > > + > > + Any cooling device has a > > + range of cooling states (i.e. > > + different levels of heat > > + dissipation). For example a > > + fan's cooling states correspond > > + to the different fan speeds > > + possible. Cooling states are > > + referred to by single unsigned > > + integers, where larger numbers > > + mean greater heat dissipation. > > + The precise set of cooling > > + states associated with a device > > + (as referred to be the > > + cooling-min-state and > > + cooling-max-state properties) > > + should be defined in a > > + particular device's binding. > > + > > + > > + > > + > > + > > + > > > > > > Cheers, > Mikko. >